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A hypnopompic state (or hypnopomp) is the state of consciousness leading out of sleep, a term coined by the psychical researcher Frederic Myers. Its twin is the hypnagogic state at sleep onset; though often conflated, the two states are not identical. The hypnagogic state is rational waking cognition trying to make sense of non-linear images and associations; the hypnopompic state is emotional and credulous dreaming cognition trying to make sense of real world stolidity. They have a different phenomenological character. Depressed frontal lobe function in the first few minutes after waking – known as "sleep inertia" – causes slowed reaction time and impaired short-term memory. Sleepers often wake confused, or speak without making sense, a phenomenon the psychologist Peter McKeller calls "hypnopompic speech". When the awakening occurs out of rapid eye movement (REM) sleep, in which most dreams occur, the hypnopompic state is sometimes accompanied by lingering vivid imagery. Some of the creative insights attributed to dreams actually happen in this moment of awakening from REM.
A Haiku Note:
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The Buddha has said,
"following the eightfold path
starts with mindfulness."
~ (0001 0001) ~
::::::::::: 11 :::::::::::
=====: 17 :=====
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The Noble Eightfold Path describes the way to the end of suffering, as it was laid out by Siddhartha Gautama. It is a practical guideline to ethical and mental development with the goal of freeing the individual from attachments and delusions; and it finally leads to understanding the truth about all things. Together with the Four Noble Truths it constitutes the gist of Buddhism. Great emphasis is put on the practical aspect, because it is only through practice that one can attain a higher level of existence and finally reach Nirvana. The eight aspects of the path are not to be understood as a sequence of single steps, instead they are highly interdependent principles that have to be seen in relationship with each other.
1. Right View
Right view is the beginning and the end of the path, it simply means to see and to understand things as they really are and to realise the Four Noble Truth. As such, right view is the cognitive aspect of wisdom. It means to see things through, to grasp the impermanent and imperfect nature of worldly objects and ideas, and to understand the law of karma and karmic conditioning. Right view is not necessarily an intellectual capacity, just as wisdom is not just a matter of intelligence. Instead, right view is attained, sustained, and enhanced through all capacities of mind. It begins with the intuitive insight that all beings are subject to suffering and it ends with complete understanding of the true nature of all things. Since our view of the world forms our thoughts and our actions, right view yields right thoughts and right actions.
2. Right Intention
While right view refers to the cognitive aspect of wisdom, right intention refers to the volitional aspect, i.e. the kind of mental energy that controls our actions. Right intention can be described best as commitment to ethical and mental self-improvement. Buddha distinguishes three types of right intentions: 1. the intention of renunciation, which means resistance to the pull of desire, 2. the intention of good will, meaning resistance to feelings of anger and aversion, and 3. the intention of harmlessness, meaning not to think or act cruelly, violently, or aggressively, and to develop compassion.
3. Right Speech
Right speech is the first principle of ethical conduct in the eightfold path. Ethical conduct is viewed as a guideline to moral discipline, which supports the other principles of the path. This aspect is not self-sufficient, however, essential, because mental purification can only be achieved through the cultivation of ethical conduct. The importance of speech in the context of Buddhist ethics is obvious: words can break or save lives, make enemies or friends, start war or create peace. Buddha explained right speech as follows: 1. to abstain from false speech, especially not to tell deliberate lies and not to speak deceitfully, 2. to abstain from slanderous speech and not to use words maliciously against others, 3. to abstain from harsh words that offend or hurt others, and 4. to abstain from idle chatter that lacks purpose or depth. Positively phrased, this means to tell the truth, to speak friendly, warm, and gently and to talk only when necessary.
4. Right Action
The second ethical principle, right action, involves the body as natural means of expression, as it refers to deeds that involve bodily actions. Unwholesome actions lead to unsound states of mind, while wholesome actions lead to sound states of mind. Again, the principle is explained in terms of abstinence: right action means 1. to abstain from harming sentient beings, especially to abstain from taking life (including suicide) and doing harm intentionally or delinquently, 2. to abstain from taking what is not given, which includes stealing, robbery, fraud, deceitfulness, and dishonesty, and 3. to abstain from sexual misconduct. Positively formulated, right action means to act kindly and compassionately, to be honest, to respect the belongings of others, and to keep sexual relationships harmless to others. Further details regarding the concrete meaning of right action can be found in the Precepts.
5. Right Livelihood
Right livelihood means that one should earn one's living in a righteous way and that wealth should be gained legally and peacefully. The Buddha mentions four specific activities that harm other beings and that one should avoid for this reason: 1. dealing in weapons, 2. dealing in living beings (including raising animals for slaughter as well as slave trade and prostitution), 3. working in meat production and butchery, and 4. selling intoxicants and poisons, such as alcohol and drugs. Furthermore any other occupation that would violate the principles of right speech and right action should be avoided.
6. Right Effort
Right effort can be seen as a prerequisite for the other principles of the path. Without effort, which is in itself an act of will, nothing can be achieved, whereas misguided effort distracts the mind from its task, and confusion will be the consequence. Mental energy is the force behind right effort; it can occur in either wholesome or unwholesome states. The same type of energy that fuels desire, envy, aggression, and violence can on the other side fuel self-discipline, honesty, benevolence, and kindness. Right effort is detailed in four types of endeavours that rank in ascending order of perfection: 1. to prevent the arising of unarisen unwholesome states, 2. to abandon unwholesome states that have already arisen, 3. to arouse wholesome states that have not yet arisen, and 4. to maintain and perfect wholesome states already arisen.
7. Right Mindfulness
Right mindfulness is the controlled and perfected faculty of cognition. It is the mental ability to see things as they are, with clear consciousness. Usually, the cognitive process begins with an impression induced by perception, or by a thought, but then it does not stay with the mere impression. Instead, we almost always conceptualise sense impressions and thoughts immediately. We interpret them and set them in relation to other thoughts and experiences, which naturally go beyond the facticity of the original impression. The mind then posits concepts, joins concepts into constructs, and weaves those constructs into complex interpretative schemes. All this happens only half consciously, and as a result we often see things obscured. Right mindfulness is anchored in clear perception and it penetrates impressions without getting carried away. Right mindfulness enables us to be aware of the process of conceptualisation in a way that we actively observe and control the way our thoughts go. Buddha accounted for this as the four foundations of mindfulness: 1. contemplation of the body, 2. contemplation of feeling (repulsive, attractive, or neutral), 3. contemplation of the state of mind, and 4. contemplation of the phenomena.
8. Right Concentration
The eighth principle of the path, right concentration, refers to the development of a mental force that occurs in natural consciousness, although at a relatively low level of intensity, namely concentration. Concentration in this context is described as one-pointedness of mind, meaning a state where all mental faculties are unified and directed onto one particular object. Right concentration for the purpose of the eightfold path means wholesome concentration, i.e. concentration on wholesome thoughts and actions. The Buddhist method of choice to develop right concentration is through the practice of meditation. The meditating mind focuses on a selected object. It first directs itself onto it, then sustains concentration, and finally intensifies concentration step by step. Through this practice it becomes natural to apply elevated levels concentration also in everyday situations.
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DESIDERATA
Go placidly amid the noise and haste, and remember what peace there may be in silence.
As far as possible, without surrender, be on good terms with all persons. Speak your truth quietly and clearly; and listen to others, even to the dull and the ignorant, they too have their story. Avoid loud and aggressive persons, they are vexations to the spirit.
If you compare yourself with others, you may become vain and bitter; for always there will be greater and lesser persons than yourself. Enjoy your achievements as well as your plans. Keep interested in your own career, however humble; it is a real possession in the changing fortunes of time.
Exercise caution in your business affairs, for the world is full of trickery. But let this not blind you to what virtue there is; many persons strive for high ideals, and everywhere life is full of heroism. Be yourself. Especially, do not feign affection. Neither be cynical about love, for in the face of all aridity and disenchantment it is perennial as the grass.
Take kindly to the counsel of the years, gracefully surrendering the things of youth. Nurture strength of spirit to shield you in sudden misfortune. But do not distress yourself with imaginings. Many fears are born of fatigue and loneliness.
Beyond a wholesome discipline, be gentle with yourself. You are a child of the universe, no less than the trees and the stars; you have a right to be here. And whether or not it is clear to you, no doubt the universe is unfolding as it should.
Therefore be at peace with God, whatever you conceive Him to be, and whatever your labors and aspirations, in the noisy confusion of life, keep peace in your soul.
With all its sham, drudgery and broken dreams, it is still a beautiful world.
Be careful. Strive to be happy.
Max Ehrmann c.1927
Current Most Interesting Pictures
"This image represents human neural stem cells from fetal cortex. Cells are stained for nuclear (Hoechst, blue), neuronal (TUJ-1, green), and astrocyte (GFAP, red) markers. Images are acquired using the InCell Analyzer 1000™. The images taken from this assay are analyzed using the Developer Toolbox™ software.
This image is one of many taken from BCI’s growing platform of human neural stem cell differentiation assays. BCI uses this assay along with several others in its neurogenesis platform to identify clinical-stage compounds, novel targets and compounds optimal for CNS indications.
"
After a vehicle ran a red light in the 6800 block of Platt Ave in West Hills, it collided with a truck driven by a 79-year-old, Mr. Dennis Platt. Mr Platt was ejected from his truck onto the asphalt with such force, he suffered severe head trauma, countless fractures, and went into cardiac arrest.
At this very moment, LAFD Fire Cadet Leo Kaufman was driving by and witnessed the accident. Leo instinctively pull over and jumped out of his vehicle into a chaotic scene. He quickly evaluated his surroundings and noticed a crowd standing around a patient that was face down, bloody, and severely injured. Bystanders stood by in shock, not knowing what to do. It was clear to Leo that if no action was taken, the patient would not survive.
Fortunately, Leo knew exactly what to do thanks to his LAFD Cadet Program CPR training. He relied on his training and rolled the trauma patient onto his back, initiating life-saving CPR. Despite some vocal people in the crowd second guessing his actions and contradicting his life-saving efforts, Cadet Kaufman worked relentlessly, performing chest compressions and circulating oxygen to the brain and heart of Mr. Platt. He did not know if his actions were going to be effective but he did know it was the only way to give this patient a chance at life.
Meanwhile, your LAFD firefighters were rushing to this scene with lights and sirens. As elite medical professionals they immediately rendered scene-safety, took over medical aid, quickly triaged, treated, and transported the patient to Kaiser hospital where a team of skilled healthcare workers took over.
Mr. Platt sustained very serious injuries which are too gruesome to share in detail but it was clear, his prognosis was not promising. Mr. Platt and his wife were told he should expect to be a quadriplegic, reliant on a wheelchair for the rest of his life. However, he regained full cognition (with mild memory loss) and is able to walk assisted (mechanical and human). His incredible rehabilitation and recovery at Kaiser Hospital is a story for another time.
This incident serves as a powerful example of the importance of Bystander CPR and the Chain of Survival. The "Chain of Survival" is a metaphor used to educate the public about their vital role in helping victims of sudden cardiac arrest (SCA).
The six steps in the chain of events that must occur in rapid succession to maximize the chances of survival from SCA are reliant on bystanders helping. Recognizing SCA, Calling 9-1-1 and Starting CPR are the first three steps and Cadet Kaufman's efforts to ensure all three were implemented gave Mr Platt his chance. The arrival of Your LAFD firefighter/paramedics ensured the remaining steps in the Chain of Survival were expediated, delivering Mr Platt into the skilled hands of the Kaiser Hospital staff.
Cadet Leo Kaufman, a 17-year-old young man, valiantly did what he was trained to do when it mattered most, and he did it extremely well!
Today, Your LAFD Fire Chief Kristen Crowley, with Mr and Mrs Platt, the LAFD crews on scene and Kaiser Hospital members present, was honored to present him with a Certificate of Appreciation which reads as follows:
" Leo J. Kaufman, LAFD Cadet. In recognition of your heroic courage and immediate assistance in saving a man's life during a cardiac arrest emergency on July 26, 2021, in the West Hills Community. The Los Angeles City Fire Department commends your extraordinary life-saving efforts of a citizen of the City of Los Angeles. Presented this 9th Day of August, 2022"
We hope reading about the actions of Cadet Leo Kaufman encourages you to Learn CPR because you could be the difference between life and death for someone needing help as desperately as Mr Platt did that fateful day
© Photo by Brandon Taylor
LAFD Event: 080922
Connect with us: LAFD.ORG | News | Facebook | Instagram | Reddit | Twitter: @LAFD @LAFDtalk
Cyanotype -- from the first batch in ToonTown, Austin -- rendered by usual means; ammonia, tea, standard formula on dirt paper.
See Also: Voting with Your Mouthhole, and Why Democracy is for Shitheels.
"The severly stripped classicism of the Kendel Milne's store on Deansgate, a most uncharacteristic work of J. S. Beaumont (1939), remains, with the Barton Arcade, the best example of retail architecture in the city."
- from the passionate, insightful and recommended Manchester, by Clare Hartwell, 2001, p33
"A sublimely monumental block with splayed corners, clad in Portland stone. In the German style of store architecture created by Messel early in the century, but stripped down. Windows are vertical strips of greenish glass blocks with a barely perceptible camber introducing subtle curves and enlivening the stark elevations with reflected light." ibid p245
Perhaps a pre-cognition of Alexander Rodchenko's unique photographic perspective? There is a helpful article in The Guardian (although the print edition included striking photographs) and a promising exhibit at the Hayward Gallery.
The Architecture Directory is useful, and somewhat daunting, list of architecture groups on flickr.
alchemists tried making gold by changing the proportions of the Four Elements in the base metals or by attempting to speed up natural growth of lesser metals into gold. Around 100 AD, Egyptian alchemist Maria Prophetissa used mercury and sulfur to try to make gold. Around 300 AD, the alchemist Zosimos, whose recipes often came to him in dreams, was working to transmute copper. “The soul of copper,” he wrote must be purified until it receives the sheen of gold and turns into the royal metal of the Sun." A technique known as "diplosis" (“doubling”) of gold became popular.
Mental retardation (MR) is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors. It has historically been defined as an Intelligence Quotient score under 70.[1] Once focused almost entirely on cognition, the definition now includes both a component relating to mental functioning and one relating to individuals' functional skills in their environment. As a result, a person with a below-average intelligence quotient may not be considered mentally retarded. Syndromic mental retardation is intellectual deficits associated with other medical and behavioral signs and symptoms. Non-syndromic mental retardation refers to intellectual deficits that appear without other abnormalities.
The terms used for this condition are subject to a process called the euphemism treadmill. This means that whatever term is chosen for this condition, it eventually becomes perceived as an insult. The terms mental retardation and mentally retarded were invented in the middle of the 20th century to replace the previous set of terms, which were deemed to have become offensive. By the end of the 20th century, these terms themselves have come to be widely seen as disparaging and politically incorrect and in need of replacement.[2] The term intellectual disability or intellectually challenged is now preferred by most advocates in most English-speaking countries. The AAIDD have defined intellectual disability to mean the same thing as mental retardation.[3] Currently, the term mental retardation is used by the World Health Organization in the ICD-10 codes, which has a section titled "Mental Retardation" (codes F70–F79). In the future, the ICD-11 is expected to replace the term mental retardation with intellectual disability, and the DSM-5 is expected to replace it with intellectual developmental disorder.[4][5] Because of its specificity and lack of confusion with other conditions, mental retardation is still sometimes used professional medical settings around the world, such as formal scientific research and health insurance paperwork.
An experiment is about to begin at the Honda Research Institute studying how robots can help children learn.
A headband tracking camera is lying on the table, and will record where the child diverts their attention – do hand and head gestures distract or aid in communication? How do children respond to a robo-voice versus one that sounds much like themselves?
Early result: the four-year olds were scared of a single step forward and back by the robot. So the feet were disabled yesterday for the rest of the study.
I also got to see ASIMO reboot a few times, with the cheery yet eerie welcome message "Wizard of Oz is connected”
When I asked how many ASIMOs there are, they looked a bit nervous and told me that is a strict company secret. Sounds like a clone army in the making. =)
Here are 20 years worth of ASIMOs, and video from the Cognitive Computing conference.
here’s a house. or an almost house. which led me to ask some questions:
is it being built or deconstructed?
what utility does it have in it’s extant form?
when we look at it are we seeing it for what it is or what it represents in terms of potential?
how do we overlook what it actually is (a bunch of wood, cobbled together) and only see what it represents (a potentially finished house)?
what amazing cognition is involved in extrapolating from a bunch of wood into a finished house?
does it have aesthetic merit in it’s extant form, and if so what?
etc.
see ‘7’.
it’s an interesting challenge, i think, to see this construction for what it is, divorced of any potential infused future utility.... tmblr.co/ZHkOLwmUDBk1
psychological / logical psycho.
Psychology "study of the mind" is an academic and applied discipline that involves the scientific study of human mental functions and behaviors. In this field, a professional practitioner or researcher is called a psychologist. Psychologists are classified as social or behavioral scientists. Psychologists attempt to understand the role of mental functions in individual and social behavior, while also exploring underlying physiological and neurological processes.
Psychologists study such topics as perception, cognition, attention, emotion, motivation, brain functioning (neuropsychology), personality, behavior, and interpersonal relationships. Some, especially depth psychologists, also consider the unconscious mind.a In addition, or in opposition, to employing empirical and deductive methods, clinical psychologists sometimes rely upon symbolic interpretation and other inductive techniques.
Psychological knowledge is applied to various spheres of human activity, including the family, education, and employment, as well as to the treatment of mental health problems.
"What seas what shores, what grey rocks and what islands
what waters lapping the bow, and the scent of pine
and the woodtrush singing through the fog
What images return, oh my daughter." --Marina, T.S. Eliot
Today was my last day of finals!! I am so relieved...it's been a really tough semester for me (especially social cognition)! I'm so glad it's over & I can't wait to feel like a kid again & be reckless and take fun photos and go running and swimming and driving around. Hopefully sooner rather than later =]
I'm listening to I sing I swim, by Seabear. It's making me want to do something memorable.
Hope you're having fun, wherever you are & whatever you're doing.
Rabbit is happier and more settled now that Fidget is in the house. She doesn't break into spasms of grief when someone leaves the building. The two of them lounge around together genially.
Mouse seems content to govern the pasture alone. She and Fidget aren't fighting when she comes down to the house, though they mount each other intermittently. (Mouse is in heat and will be spayed in a couple of weeks.)
After Mouse has been down at the house for an hour or so, she sits by the gate and asks to be taken back to her pasture. I was surprised the first time that she did that, but after all, Pyrs were bred to live a life that humans would describe as "solitary". Probably Pyrs aren't "alone" if they have their flock.
Our fancy primate brains have decided that they're still going to get Mouse a pup after she has recovered from being spayed. But that may just be a projection of hominid desires onto a canid species.
Mouse may very well be saying * PLEASE * DON'T * GET * ME * A * PUPPY *.
But of course, we know what's best for her. :)
We have so much control over dogs' lives that I hope we do know what's best for them. The most common understanding of human-dog relationships can be summarized as follows: "People think dogs are people, and dogs think people are dogs." It's an imperfect theory, but it explains a lot, and one of the reasons that we bother with theories is that they have explanatory power.
Coming at the problem from another direction, Konrad Lorenz -- a brilliant ethologist, and perhaps not incidentally, a bit of a Nazi in his younger days -- convinced many of us to think of dogs as pack-oriented wolflets who inhabit a genetically determined landscape of dominance and submission. Genetic determinism (sociobiology) is a first-rate tool for studying ants, but it breaks down in ludicrous ways when applied to organisms that are as complex and individuated as dogs.
Besides, there is little resemblance between wolf and dog packs. Wolf packs are families with a straightforward breeding structure. Most or all of a pack's members are relatively recent descendants of a single breeding pair.
On the other hand, dog packs, whether made up of strays or ferals, are pick-up gangs of relatively distantly related individuals. Each pack has a more or less random genetic structure, except of course that they're all dogs. It's not too surprising that wolf-pack behavior is amenable to study in terms of social genetics, but maybe it's a mistake to apply wolfish conclusions to packs that lack a coherent genetic structure. Maybe the pack-mentality trainers get their results for reasons entirely unrelated to their theoretical model.
Further, analyzing dogs in terms of pack dynamics leads us to overemphasize dominance and submission at the expense of a rich panoply of sensory and investigatory behaviors. (After all, dogs spend a vanishingly tiny fraction of their time working out dominance relationships by comparison to the time spent wandering, watching, exploring, sniffing, licking, rolling and mooching.)
So I have been thinking that the pack model of dog behavior offers relatively little in the way of explanatory power, and that it leads us to behave strangely and ineffectually toward our doggie friends.
(A lot of this comes straight out of Alexandra Horowitz's Inside of a Dog, a book-length treatment of canine perception and cognition. Recommended.)
Once again my friend Suman (sqrphotos) has allowed me to work with his beautiful and amazing photos, I'm very grateful for his generosity.
This is the work that I've been doing so far: Suman's Birds in texture
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Texture background with my deepest gratitude to: Playingwithbrushes Dirtier Thanks a lot Renee !!
In May 2018 I was invited as artist on board on Kleronia, a 18 mt. cutter, in team with a video maker, a writer and a few skippers, to support the “Cognition in the wind” research project directed by Roberto Casati (Institut Jean Nicod, CNRS ENS EHESS, Paris). We navigate between Rome, the Pontine Islands and Gaeta. Watch a video here: www.youtube.com/watch?v=7TpY-AeXRNk
The grey parrot (Psittacus erithacus), also known as the Congo grey parrot, Congo African grey parrot or African grey parrot, is an Old World parrot in the family Psittacidae. The Timneh parrot (Psittacus timneh) once was identified as a subspecies of the grey parrot, but has since been elevated to a full species.
Taxonomy
The grey parrot was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. He placed it with all the other parrots in the genus Psittacus and coined the binomial name Psittacus erithacus. Linnaeus erroneously specified the type locality as "Guinea": the locality was later designated as Ghana in West Africa. The genus name is Latin for "parrot". The specific epithet erithacus is Latin and is derived from the Ancient Greek εριθακος (erithakos) for an unknown bird that was said to mimic human sounds, perhaps the black redstart. The species is monotypic: no subspecies are recognised.
The Timneh parrot was formerly treated as a subspecies of the grey parrot but is now considered to be a separate species based mainly on the results from a genetic and morphological study published in 2007. Although Linnaeus placed all the parrots known to him in the genus Psittacus, only the grey parrot and the Timneh parrot are now assigned to this genus.
Description
The grey parrot is a medium-sized, predominantly grey, black-billed parrot. Its typical weight is 400 g (14 oz), with an approximate length of 33 cm (13 in), and a wingspan of 46–52 cm (18–20+1⁄2 in). The grey colour on the head and wings is generally darker than its body. The head and body feathers have slight white edges. The tail feathers are red.
Due to selection by parrot breeders, some grey parrots are partly or completely red. Both sexes appear similar. The colouration of juveniles is similar to that of adults, but typically their eyes are dark grey to black, in comparison to the yellow irises around dark pupils of the adult birds, and their undertail coverts are tinged with grey. Adults weigh 418–526 g (14+3⁄4–18+1⁄2 oz).
Grey parrots may live for 40–60 years in captivity, although their mean lifespan in the wild appears to be shorter—approximately 23 years. They start breeding at an age of 3–5 years and lay 3-5 eggs per brood.
Distribution and habitat
The grey parrot is native to equatorial Africa, including Angola, Cameroon, the Congo, Gabon, Ivory Coast, Ghana, Kenya, and Uganda. The species is found inside a range from Kenya to the eastern part of the Ivory Coast. Current estimates for the global population are uncertain and range from 630,000 to 13 million birds. Populations are decreasing worldwide. The species seems to favor dense forests, but can also be found at forest edges and in more open vegetation types, such as gallery and savanna forests.
A population study published in 2015 found that the species had been "virtually eliminated" from Ghana with numbers declining 90 to 99% since 1992. They were found in only 10 of 42 forested areas, and three roosts that once held 700–1200 birds each, now had only 18 in total. Local people mainly blamed the pet trade and the felling of timber for the decline. Populations are thought to be stable in Cameroon. In the Congo, an estimated 15,000 are taken every year for the pet trade, from the eastern part of the country, although the annual quota is stated to be 5,000.
Grey parrots have escaped or been deliberately released into Florida, U.S., but no evidence indicates that the population is breeding naturally.
Behaviour and ecology in the wild
Little is known about the behaviour and activities of these birds in the wild. In addition to a lack of research funding, it can be particularly difficult to study these birds in wild situations due to their status as prey animals, which leads them to have rather secretive personalities. It has been shown that wild greys may also imitate a wide variety of sounds they hear, much like their captive relatives. In the Democratic Republic of the Congo, two greys sound-recorded while roosting reportedly had a repertoire of over 200 different calls, including nine imitations of other wild bird songs and one of a bat.
Feeding
Grey parrots are mainly frugivorous, with most of their diet consisting of fruit, nuts, and seeds, including oil palm fruit. They sometimes also eat flowers and tree bark, as well as insects and snails. In the wild, the grey parrot is partly a ground feeder.
Breeding
Grey parrots are monogamous breeders who nest in tree cavities. Each mated pair of parrots needs their own tree for their nest. The hen lays three to five eggs, which she incubates for 30 days while being fed by her mate. The adults defend their nesting sites.
Grey parrot chicks require feeding and care from their parents in the nest. The parents take care of them until 4–5 weeks after they are fledged. Young leave the nest at the age of 12 weeks. Little is known about the courtship behaviour of this species in the wild.[9] They weigh 12–14 g (7⁄16–1⁄2 oz) at hatching and 372–526 g (13+1⁄8–18+1⁄2 oz) when they leave their parents.
Conservation
Natural predators for this species include palm-nut vultures and several raptors. Monkeys target eggs and the young for food.
Humans are by far the largest threat to wild grey populations. Between 1994 and 2003, more than 359,000 grey parrots were traded on the international market. Approximately 21% of the wild population was being harvested every year. Mortality rates are extremely high between the time they are captured and they reach the market, ranging from 60 to 66%. This species also is hunted for its meat and for its body parts, which are used in traditional medicines. As a result of the extensive harvest of wild birds, in addition to habitat loss, this species is believed to be undergoing a rapid decline in the wild and therefore, has been rated as endangered by the International Union for Conservation of Nature.
In October 2016, the Convention on the International Trade of Endangered Fauna and Flora (CITES) extended the highest level of protection to grey parrots by listing the species under Appendix 1, which regulates international trade in the species.
In 2021, the Kenyan government held a short amnesty, during which grey parrot owners could pay a fee to obtain a permit for their birds and facilitate legal ownership. Following the expiry of this time period, it is now illegal to own this species without a permit.
In captivity
The species is common in captivity and regularly kept by humans as a companion parrot, prized for its ability to mimic human speech, which makes it one of the most popular avian pets. An escaped pet in Japan was returned to his owner after repeating the owner's name and address.
Grey parrots are notorious for mimicking noises heard in their environment and using them tirelessly. They are highly intelligent birds, needing extensive behavioral and social enrichment as well as extensive attention in captivity or else they may become distressed. Feather plucking is a common symptom seen among such distressed grey parrots, affecting up to 40% of captive individuals. They may also be prone to behavioural problems due to their sensitive nature. Social isolation hastens stress and aging.
The grey parrot is a highly social species which relies on a flock-type structure, even when raised in captivity. Because they are so dependent on the other birds within their flock, much of their speech and vocal ability is acquired through interaction with the humans with whom they reside. Both wild and captive parrots have been shown to use contact calls, which allow them to interact with their flock mates and communicate information about their location, detection of predators, availability of food, and safety status. In addition, contact calls are used to form strong social bonds with their flock mates, or in the case of captive greys, with their human housemates. In captivity, they have been shown to display communicative competence, meaning they not only use human language correctly, but also in such a way that is appropriate for the social situation which they are in.
Diet
In captivity, they may be fed bird pellets, a variety of fruits such as pear, orange, pomegranate, apple, and banana, and vegetables such as carrot, cooked sweet potato, celery, fresh kale, peas, and green beans. They also need a source of calcium.
Disease
Grey parrots in captivity have been observed to be susceptible to fungal infections, bacterial infections, nutritional insufficiency, malignant tumors, psittacine beak and feather disease, tapeworms, and blood-worms. Young grey parrots are more commonly infected by psittacine beak and feather disease than adults. Infected birds show symptoms such as loss of appetite, fluffy feathers, sluggishness, and reduced walking abilities due to brittle bones.
Grey parrots are more likely to have rhinitis,[clarification needed] an inflammatory and infectious disease of the nasal cavity. Birds may exhibit signs like wheezing, sneezing, nasal snuffling, and swelling or occlusion of the nares. Treatment options include gentle debridement and nasal irrigation.
Intelligence and cognition
Grey parrots are highly intelligent and are considered by many to be one of the most intelligent species of psittacines. Many individuals have been shown to perform at the cognitive level of a four- to six-year-old human child in some tasks. Several studies have been conducted, indicating a suite of higher-level cognitive abilities. Experiments have shown that grey parrots can learn number sequences and can learn to associate human voices with the faces of the humans who create them. It has been reported that grey parrots are capable of using existing known English words to create new labels for objects when the bird does not know the name of the object. For example "banerry" ("banana" + "cherry") for "apple", "banana crackers" for "dried banana chips" or "yummy bread" for "cake".
The American scientist Irene Pepperberg's research with Alex the parrot showed his ability to learn more than 100 words, differentiating between objects, colours, materials and shapes. Pepperberg spent several decades working with Alex, and wrote numerous scientific papers on experiments performed, indicating his advanced cognitive abilities. One such study found that Alex had the ability to add numbers as well as having a zero-like concept, similar to that of young children and apes.
In addition to their striking cognitive abilities, grey parrots have displayed altruistic behavior and concern for others. Researchers found that while blue-headed macaws were unlikely to share a nut with other members of their own species, grey parrots would actively give their conspecific partner a nut, even if it meant that they would not be able to get one themselves. When the roles were reversed, their partners were overwhelmingly likely to return the favor, foregoing their own nut to their partner's benefits. This indicates not only a display of selflessness but also an act of reciprocity.
A 2012 study demonstrated that captive grey parrots have individual musical preferences. When presented with the opportunity to choose between two different pieces of music via a touch screen monitor located in their cage, the two birds in the test consistently chose different songs, to which they then danced and sang along. Some pet grey parrots have also been observed using the music feature of smart speakers (such as Alexa or Amazon Echo) to verbally request playback of specific favored songs.
Some research has shown that foot preference can be linked to the number of words a particular parrot may know and use. Researchers found that grey parrots who prefer to use their right foot showed a marked increase in the number of words within their lexicon as compared to parrots who were left-footed. Scientists postulate that parrots may have lateralization of brain function, much like mammals do.
In two murder trials, one in 1993 and another in 2017, there was consideration to use the deceased victim's pet grey parrot's "testimony" as evidence due to the pet parrot's witnessing and repeating the victim's last words. In the 1993 murder trial of Gary Joseph Rasp, the defendant was accused of murdering Jane Gill. Public defender Charles Ogulnik wanted to use Jane's pet grey parrot Max as evidence to prove Gary's innocence due to Max repeating Jane's last words "Richard, no, no, no!". In the 2017 murder trial of Glenna Duram, the defendant is accused of murdering her husband Martin Duram. The prosecutor was exploring the possibility of using the couple's pet parrot Bud as evidence when Bud kept repeating Martin's last words "Don't fucking shoot."
Mutations
Grey mutations occur naturally in the wild, such as the Blue Ino (albino), the Incomplete Ino, and the Blue varietals. The Blue Ino is all white. The Incomplete Ino has light pigmentation. The Blue has a white tail.
Breeders from South Africa, Australia, New Zealand, and Scandinavia have bred greys intensively since the 1800s. These bred varieties include the Red Pied, F2 Pied, Grizzles, Ino, Incomplete, Parino, Lutino, Cinnamon, and Red Factor. South African bird breeder Von van Antwerpen and New Zealand partner Jaco Bosman selected F2 Pieds and created the first Red Factor Greys. They are rare, may be predominantly red-pigmented, and vary in price depending upon the extent of the red plumage displayed.
History
The domestication of grey parrots has a history dating to 2000 B.C., depicting native birds in Egyptian hieroglyphics as pets. They were used for values by the Greeks and the Romans who kept them in birdcages. The grey parrots, due to recent years of illegal trading, have been classified as Endangered in 2016 by the IUCN Red List.
These Seven Principles of Human Learning taken from the National Academies Press free ebook Learning and Understanding (2002).
"During the last four decades, scientists have engaged in research that has increased our understanding of human cognition, providing greater insight into how knowledge is organized, how experience shapes understanding, how people monitor their own understanding, how learners differ from one another, and how people acquire expertise. From this emerging body of research, scientists and others have been able to synthesize a number of underlying principles of human learning. This growing understanding of how people learn has the potential to influence significantly the nature of education and its outcomes."
Image licensed under Creative Commons by happeningfish: www.flickr.com/photos/happeningfish/3007746661/
Testosterone
The chemical structure of testosterone.
A ball-and-stick model of testosterone.
Names
IUPAC name
17β-Hydroxyandrost-4-en-3-one
Systematic IUPAC name
(8R,9S,10R,13S,14S,17S)-17-Hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one
Other names
Androst-4-en-17β-ol-3-one
Identifiers
CAS Number
58-22-0 ☑
3D model (JSmol)
Interactive image
ChEBI
CHEBI:17347 ☑
ChEMBL
ChEMBL386630 ☑
ChemSpider
5791 ☑
DrugBank
DB00624 ☑
ECHA InfoCard100.000.336
KEGG
D00075 ☑
PubChem CID
6013
UNII
3XMK78S47O ☑
InChI[show]
SMILES[show]
Properties
Chemical formula
C19H28O2
Molar mass288.431 g·mol−1
Melting point155 °C
Pharmacology
ATC code
G03BA03 (WHO)
License data
EU EMA: by INN
Routes of
administration
Transdermal (gel, cream, solution, patch), by mouth (as testosterone undecanoate), in the cheek, intranasal (gel), intramuscular injection (as esters), subcutaneous pellets
Pharmacokinetics:
Bioavailability
Oral: very low (due to extensive first pass metabolism)
Protein binding
97.0–99.5% (to SHBG and albumin)[1]
Metabolism
Liver (mainly reduction and conjugation)
Biological half-life
2–4 hours[citation needed]
Excretion
Urine (90%), feces (6%)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Testosterone is the primary male sex hormone and an anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.[2] In addition, testosterone is involved in health and well-being,[3] and the prevention of osteoporosis.[4] Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss.
Testosterone is a steroid from the androstane class containing a keto and hydroxyl groups at the three and seventeen positions respectively. It is biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites.[5] It exerts its action through binding to and activation of the androgen receptor.[5] In humans and most other vertebrates, testosterone is secreted primarily by the testicles of males and, to a lesser extent, the ovaries of females. On average, in adult males, levels of testosterone are about 7 to 8 times as great as in adult females.[6] As the metabolism of testosterone in males is more pronounced, the daily production is about 20 times greater in men.[7][8] Females are also more sensitive to the hormone.[9]
In addition to its role as a natural hormone, testosterone is used as a medication, for instance in the treatment of low testosterone levels in men and breast cancer in women.[10] Since testosterone levels decrease as men age, testosterone is sometimes used in older men to counteract this deficiency. It is also used illicitly to enhance physique and performance, for instance in athletes.
Contents
1Biological effects
1.1Before birth
1.2Early infancy
1.3Before puberty
1.4Pubertal
1.5Adult
1.6Aggression and criminality
1.7Brain
2Medical use
3Biological activity
3.1Steroid hormone activity
3.2Neurosteroid activity
4Biochemistry
4.1Biosynthesis
4.2Distribution
4.3Metabolism
4.4Levels
5Measurement
6History
7Other animals
8See also
9References
10Further reading
Biological effects[edit]
In general, androgens such as testosterone promote protein synthesis and thus growth of tissues with androgen receptors.[11] Testosterone can be described as having virilising and anabolic effects (though these categorical descriptions are somewhat arbitrary, as there is a great deal of mutual overlap between them).[12]
Anabolic effects include growth of muscle mass and strength, increased bone density and strength, and stimulation of linear growth and bone maturation.
Androgenic effects include maturation of the sex organs, particularly the penis and the formation of the scrotum in the fetus, and after birth (usually at puberty) a deepening of the voice, growth of facial hair (such as the beard) and axillary (underarm) hair. Many of these fall into the category of male secondary sex characteristics.
Testosterone effects can also be classified by the age of usual occurrence. For postnatal effects in both males and females, these are mostly dependent on the levels and duration of circulating free testosterone.
Before birth[edit]
Effects before birth are divided into two categories, classified in relation to the stages of development.
The first period occurs between 4 and 6 weeks of the gestation. Examples include genital virilisation such as midline fusion, phallic urethra, scrotal thinning and rugation, and phallic enlargement; although the role of testosterone is far smaller than that of dihydrotestosterone. There is also development of the prostate gland and seminal vesicles.
During the second trimester, androgen level is associated with sex formation.[13] This period affects the femininization or masculinization of the fetus and can be a better predictor of feminine or masculine behaviours such as sex typed behaviour than an adult's own levels. A mother's testosterone level during pregnancy is correlated with her daughter's sex-typical behavior as an adult, and the correlation is even stronger than with the daughter's own adult testosterone level.[14]
Early infancy[edit]
Early infancy androgen effects are the least understood. In the first weeks of life for male infants, testosterone levels rise. The levels remain in a pubertal range for a few months, but usually reach the barely detectable levels of childhood by 4–7 months of age.[15][16] The function of this rise in humans is unknown. It has been theorized that brain masculinization is occurring since no significant changes have been identified in other parts of the body.[17] The male brain is masculinized by the aromatization of testosterone into estrogen, which crosses the blood–brain barrier and enters the male brain, whereas female fetuses have α-fetoprotein, which binds the estrogen so that female brains are not affected.[18]
Before puberty[edit]
Before puberty effects of rising androgen levels occur in both boys and girls. These include adult-type body odor, increased oiliness of skin and hair, acne, pubarche (appearance of pubic hair), axillary hair (armpit hair), growth spurt, accelerated bone maturation, and facial hair.[19]
Pubertal[edit]
Pubertal effects begin to occur when androgen has been higher than normal adult female levels for months or years. In males, these are usual late pubertal effects, and occur in women after prolonged periods of heightened levels of free testosterone in the blood. The effects include:[19][20]
Growth of spermatogenic tissue in testicles, male fertility, penis or clitoris enlargement, increased libido and frequency of erection or clitoral engorgement occurs. Growth of jaw, brow, chin, and nose and remodeling of facial bone contours, in conjunction with human growth hormone occurs.[21] Completion of bone maturation and termination of growth. This occurs indirectly via estradiol metabolites and hence more gradually in men than women. Increased muscle strength and mass, shoulders become broader and rib cage expands, deepening of voice, growth of the Adam's apple. Enlargement of sebaceous glands. This might cause acne, subcutaneous fat in face decreases. Pubic hair extends to thighs and up toward umbilicus, development of facial hair (sideburns, beard, moustache), loss of scalp hair (androgenetic alopecia), increase in chest hair, periareolar hair, perianal hair, leg hair, armpit hair.
Adult[edit]
Testosterone is necessary for normal sperm development. It activates genes in Sertoli cells, which promote differentiation of spermatogonia. It regulates acute HPA (hypothalamic–pituitary–adrenal axis) response under dominance challenge.[22] Androgen including testosterone enhances muscle growth. Testosterone also regulates the population of thromboxane A2 receptors on megakaryocytes and platelets and hence platelet aggregation in humans.[23][24]
Adult testosterone effects are more clearly demonstrable in males than in females, but are likely important to both sexes. Some of these effects may decline as testosterone levels might decrease in the later decades of adult life.[25]
Health risks[edit]
Testosterone does not appear to increase the risk of developing prostate cancer. In people who have undergone testosterone deprivation therapy, testosterone increases beyond the castrate level have been shown to increase the rate of spread of an existing prostate cancer.[26][27][28]
Conflicting results have been obtained concerning the importance of testosterone in maintaining cardiovascular health.[29][30] Nevertheless, maintaining normal testosterone levels in elderly men has been shown to improve many parameters that are thought to reduce cardiovascular disease risk, such as increased lean body mass, decreased visceral fat mass, decreased total cholesterol, and glycemic control.[31]
High androgen levels are associated with menstrual cycle irregularities in both clinical populations and healthy women.[32]
Sexual arousal[edit]
See also: Hormones and sexual arousal
When testosterone and endorphins in ejaculated semen meet the cervical wall after sexual intercourse, females receive a spike in testosterone, endorphin, and oxytocin levels, and males after orgasm during copulation experience an increase in endorphins and a marked increase in oxytocin levels. This adds to the hospitable physiological environment in the female internal reproductive tract for conceiving, and later for nurturing the conceptus in the pre-embryonic stages, and stimulates feelings of love, desire, and paternal care in the male (this is the only time male oxytocin levels rival a female's).[citation needed]
Testosterone levels follow a nyctohemeral rhythm that peaks early each day, regardless of sexual activity.[33]
There are positive correlations between positive orgasm experience in women and testosterone levels where relaxation was a key perception of the experience. There is no correlation between testosterone and men's perceptions of their orgasm experience, and also no correlation between higher testosterone levels and greater sexual assertiveness in either sex.[34]
Sexual arousal and masturbation in women produce small increases in testosterone concentrations.[35] The plasma levels of various steroids significantly increase after masturbation in men and the testosterone levels correlate to those levels.[36]
Mammalian studies[edit]
Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. When testosterone-deprived rats were given medium levels of testosterone, their sexual behaviors (copulation, partner preference, etc.) resumed, but not when given low amounts of the same hormone. Therefore, these mammals may provide a model for studying clinical populations among humans suffering from sexual arousal deficits such as hypoactive sexual desire disorder.[37]
In every mammalian species examined demonstrated a marked increase in a male's testosterone level upon encountering a novel female. The reflexive testosterone increases in male mice is related to the male's initial level of sexual arousal.[38]
In non-human primates, it may be that testosterone in puberty stimulates sexual arousal, which allows the primate to increasingly seek out sexual experiences with females and thus creates a sexual preference for females.[39] Some research has also indicated that if testosterone is eliminated in an adult male human or other adult male primate's system, its sexual motivation decreases, but there is no corresponding decrease in ability to engage in sexual activity (mounting, ejaculating, etc.).[39]
In accordance with sperm competition theory, testosterone levels are shown to increase as a response to previously neutral stimuli when conditioned to become sexual in male rats.[40] This reaction engages penile reflexes (such as erection and ejaculation) that aid in sperm competition when more than one male is present in mating encounters, allowing for more production of successful sperm and a higher chance of reproduction.
Males[edit]
In men, higher levels of testosterone are associated with periods of sexual activity.[41][42]
Men who watch a sexually explicit movie have an average increase of 35% in testosterone, peaking at 60–90 minutes after the end of the film, but no increase is seen in men who watch sexually neutral films.[43] Men who watch sexually explicit films also report increased motivation, competitiveness, and decreased exhaustion.[44] A link has also been found between relaxation following sexual arousal and testosterone levels.[45]
Men's levels of testosterone, a hormone known to affect men's mating behaviour, changes depending on whether they are exposed to an ovulating or nonovulating woman's body odour. Men who are exposed to scents of ovulating women maintained a stable testosterone level that was higher than the testosterone level of men exposed to nonovulation cues. Testosterone levels and sexual arousal in men are heavily aware of hormone cycles in females.[46] This may be linked to the ovulatory shift hypothesis,[47] where males are adapted to respond to the ovulation cycles of females by sensing when they are most fertile and whereby females look for preferred male mates when they are the most fertile; both actions may be driven by hormones.
Females[edit]
Androgens may modulate the physiology of vaginal tissue and contribute to female genital sexual arousal.[48] Women's level of testosterone is higher when measured pre-intercourse vs pre-cuddling, as well as post-intercourse vs post-cuddling.[49] There is a time lag effect when testosterone is administered, on genital arousal in women. In addition, a continuous increase in vaginal sexual arousal may result in higher genital sensations and sexual appetitive behaviors.[50]
When females have a higher baseline level of testosterone, they have higher increases in sexual arousal levels but smaller increases in testosterone, indicating a ceiling effect on testosterone levels in females. Sexual thoughts also change the level of testosterone but not level of cortisol in the female body, and hormonal contraceptives may affect the variation in testosterone response to sexual thoughts.[51]
Testosterone may prove to be an effective treatment in female sexual arousal disorders,[52] and is available as a dermal patch. There is no FDA approved androgen preparation for the treatment of androgen insufficiency; however, it has been used off-label to treat low libido and sexual dysfunction in older women. Testosterone may be a treatment for postmenopausal women as long as they are effectively estrogenized.[52]
Romantic relationships[edit]
Falling in love decreases men's testosterone levels while increasing women's testosterone levels. There has been speculation that these changes in testosterone result in the temporary reduction of differences in behavior between the sexes.[53] However, it is suggested that after the "honeymoon phase" ends—about four years into a relationship—this change in testosterone levels is no longer apparent.[53] Men who produce less testosterone are more likely to be in a relationship[54] or married,[55] and men who produce more testosterone are more likely to divorce;[55] however, causality cannot be determined in this correlation. Marriage or commitment could cause a decrease in testosterone levels.[56] Single men who have not had relationship experience have lower testosterone levels than single men with experience. It is suggested that these single men with prior experience are in a more competitive state than their non-experienced counterparts.[57] Married men who engage in bond-maintenance activities such as spending the day with their spouse/and or child have no different testosterone levels compared to times when they do not engage in such activities. Collectively, these results suggest that the presence of competitive activities rather than bond-maintenance activities are more relevant to changes in testosterone levels.[58]
Men who produce more testosterone are more likely to engage in extramarital sex.[55] Testosterone levels do not rely on physical presence of a partner; testosterone levels of men engaging in same-city and long-distance relationships are similar.[54] Physical presence may be required for women who are in relationships for the testosterone–partner interaction, where same-city partnered women have lower testosterone levels than long-distance partnered women.[59]
Fatherhood[edit]
Fatherhood decreases testosterone levels in men, suggesting that the emotions and behavior tied to decreased testosterone promote paternal care. In humans and other species that utilize allomaternal care, paternal investment in offspring is beneficial to said offspring's survival because it allows the parental dyad to raise multiple children simultaneously. This increases the reproductive fitness of the parents, because their offspring are more likely to survive and reproduce. Paternal care increases offspring survival due to increased access to higher quality food and reduced physical and immunological threats.[60] This is particularly beneficial for humans since offspring are dependent on parents for extended periods of time and mothers have relatively short inter-birth intervals.[61] While extent of paternal care varies between cultures, higher investment in direct child care has been seen to be correlated with lower average testosterone levels as well as temporary fluctuations.[62] For instance, fluctuation in testosterone levels when a child is in distress has been found to be indicative of fathering styles. If a father's testosterone levels decrease in response to hearing their baby cry, it is an indication of empathizing with the baby. This is associated with increased nurturing behavior and better outcomes for the infant.[63]
Motivation[edit]
Testosterone levels play a major role in risk-taking during financial decisions.[64][65]
Aggression and criminality [edit]
See also: Aggression § Testosterone, and Biosocial criminology
Most studies support a link between adult criminality and testosterone, although the relationship is modest if examined separately for each sex. Nearly all studies of juvenile delinquency and testosterone are not significant. Most studies have also found testosterone to be associated with behaviors or personality traits linked with criminality such as antisocial behavior and alcoholism. Many studies have also been done on the relationship between more general aggressive behavior/feelings and testosterone. About half the studies have found a relationship and about half no relationship.[66]
Testosterone is only one of many factors that influence aggression and the effects of previous experience and environmental stimuli have been found to correlate more strongly. A few studies indicate that the testosterone derivative estradiol (one form of estrogen) might play an important role in male aggression.[66][67][68][69] Studies have also found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus.[70]
The sexual hormone can encourage fair behavior. For the study, subjects took part in a behavioral experiment where the distribution of a real amount of money was decided. The rules allowed both fair and unfair offers. The negotiating partner could subsequently accept or decline the offer. The fairer the offer, the less probable a refusal by the negotiating partner. If no agreement was reached, neither party earned anything. Test subjects with an artificially enhanced testosterone level generally made better, fairer offers than those who received placebos, thus reducing the risk of a rejection of their offer to a minimum. Two later studies have empirically confirmed these results.[71][72][73] However men with high testosterone were significantly 27% less generous in an ultimatum game.[74] The Annual NY Academy of Sciences has also found anabolic steroid use which increase testosterone to be higher in teenagers, and this was associated with increased violence.[75] Studies have also found administered testosterone to increase verbal aggression and anger in some participants.[76]
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.[77] The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.[77] Thus it is the challenge of competition among males of the species that facilitates aggression and violence.[77] Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.[77] The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.[77]
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".[78][79] Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.[78] The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.[80] Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.[81][82][83][84][85]
The rise in testosterone levels during competition predicted aggression in males but not in females.[86] Subjects who interacted with hand guns and an experimental game showed rise in testosterone and aggression.[87] Natural selection might have evolved males to be more sensitive to competitive and status challenge situations and that the interacting roles of testosterone are the essential ingredient for aggressive behaviour in these situations.[88] Testosterone produces aggression by activating subcortical areas in the brain, which may also be inhibited or suppressed by social norms or familial situations while still manifesting in diverse intensities and ways through thoughts, anger, verbal aggression, competition, dominance and physical violence.[89] Testosterone mediates attraction to cruel and violent cues in men by promoting extended viewing of violent stimuli.[90] Testosterone specific structural brain characteristic can predict aggressive behaviour in individuals.[91]
Estradiol is known to correlate with aggression in male mice.[92] Moreover, the conversion of testosterone to estradiol regulates male aggression in sparrows during breeding season.[93] Rats who were given anabolic steroids that increase testosterone were also more physically aggressive to provocation as a result of "threat sensitivity".[94]
Brain[edit]
The brain is also affected by this sexual differentiation;[13] the enzyme aromatase converts testosterone into estradiol that is responsible for masculinization of the brain in male mice. In humans, masculinization of the fetal brain appears, by observation of gender preference in patients with congenital diseases of androgen formation or androgen receptor function, to be associated with functional androgen receptors.[95]
There are some differences between a male and female brain (possibly the result of different testosterone levels), one of them being size: the male human brain is, on average, larger.[96] Men were found to have a total myelinated fiber length of 176 000 km at the age of 20, whereas in women the total length was 149 000 km (approx. 15% less).[97]
No immediate short term effects on mood or behavior were found from the administration of supraphysiologic doses of testosterone for 10 weeks on 43 healthy men.[98] A correlation between testosterone and risk tolerance in career choice exists among women.[64][99]
Attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans. Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimer's type,[100][101][102][103] a key argument in life extension medicine for the use of testosterone in anti-aging therapies. Much of the literature, however, suggests a curvilinear or even quadratic relationship between spatial performance and circulating testosterone,[104] where both hypo- and hypersecretion (deficient- and excessive-secretion) of circulating androgens have negative effects on cognition.
Medical use[edit]
Main article: Testosterone (medication)
Testosterone is used as a medication for the treatment of males with too little or no natural testosterone production, certain forms of breast cancer,[10] and gender dysphoria in transgender men. This is known as hormone replacement therapy (HRT) or testosterone replacement therapy (TRT), which maintains serum testosterone levels in the normal range. Decline of testosterone production with age has led to interest in androgen replacement therapy.[105] It is unclear if the use of testosterone for low levels due to aging is beneficial or harmful.[106]
Testosterone is included in the World Health Organization's list of essential medicines, which are the most important medications needed in a basic health system.[107] It is available as a generic medication.[10] The price depends on the form of testosterone used.[108] It can be administered as a cream or transdermal patch that is applied to the skin, by injection into a muscle, as a tablet that is placed in the cheek, or by ingestion.[10]
Common side effects from testosterone medication include acne, swelling, and breast enlargement in males.[10] Serious side effects may include liver toxicity, heart disease, and behavioral changes.[10] Women and children who are exposed may develop virilization.[10] It is recommended that individuals with prostate cancer not use the medication.[10] It can cause harm if used during pregnancy or breastfeeding.[10]
Biological activity[edit]
Steroid hormone activity[edit]
The effects of testosterone in humans and other vertebrates occur by way of multiple mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors.[109][110] Androgens such as testosterone have also been found to bind to and activate membrane androgen receptors.[111][112][113]
Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than testosterone, so that its androgenic potency is about 5 times that of T.[114] The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects.
Androgen receptors occur in many different vertebrate body system tissues, and both males and females respond similarly to similar levels. Greatly differing amounts of testosterone prenatally, at puberty, and throughout life account for a share of biological differences between males and females.
The bones and the brain are two important tissues in humans where the primary effect of testosterone is by way of aromatization to estradiol. In the bones, estradiol accelerates ossification of cartilage into bone, leading to closure of the epiphyses and conclusion of growth. In the central nervous system, testosterone is aromatized to estradiol. Estradiol rather than testosterone serves as the most important feedback signal to the hypothalamus (especially affecting LH secretion).[115] In many mammals, prenatal or perinatal "masculinization" of the sexually dimorphic areas of the brain by estradiol derived from testosterone programs later male sexual behavior.[116]
Neurosteroid activity[edit]
Testosterone, via its active metabolite 3α-androstanediol, is a potent positive allosteric modulator of the GABAA receptor.[117]
Testosterone has been found to act as an antagonist of the TrkA and p75NTR, receptors for the neurotrophin nerve growth factor (NGF), with high affinity (around 5 nM).[118][119][120] In contrast to testosterone, DHEA and DHEA sulfate have been found to act as high-affinity agonists of these receptors.[118][119][120]
Testosterone is an antagonist of the sigma σ1 receptor (Ki = 1,014 or 201 nM).[121] However, the concentrations of testosterone required for binding the receptor are far above even total circulating concentrations of testosterone in adult males (which range between 10 and 35 nM).[122]
Biochemistry[edit]
Human steroidogenesis, showing testosterone near bottom.[123]
Biosynthesis[edit]
Like other steroid hormones, testosterone is derived from cholesterol (see figure).[124] The first step in the biosynthesis involves the oxidative cleavage of the side-chain of cholesterol by cholesterol side-chain cleavage enzyme (P450scc, CYP11A1), a mitochondrial cytochrome P450 oxidase with the loss of six carbon atoms to give pregnenolone. In the next step, two additional carbon atoms are removed by the CYP17A1 (17α-hydroxylase/17,20-lyase) enzyme in the endoplasmic reticulum to yield a variety of C19 steroids.[125] In addition, the 3β-hydroxyl group is oxidized by 3β-hydroxysteroid dehydrogenase to produce androstenedione. In the final and rate limiting step, the C17 keto group androstenedione is reduced by 17β-hydroxysteroid dehydrogenase to yield testosterone.
The largest amounts of testosterone (>95%) are produced by the testes in men,[2] while the adrenal glands account for most of the remainder. Testosterone is also synthesized in far smaller total quantities in women by the adrenal glands, thecal cells of the ovaries, and, during pregnancy, by the placenta.[126] In the testes, testosterone is produced by the Leydig cells.[127] The male generative glands also contain Sertoli cells, which require testosterone for spermatogenesis. Like most hormones, testosterone is supplied to target tissues in the blood where much of it is transported bound to a specific plasma protein, sex hormone-binding globulin (SHBG).
Regulation[edit]
Hypothalamic–pituitary–testicular axis
In males, testosterone is synthesized primarily in Leydig cells. The number of Leydig cells in turn is regulated by luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In addition, the amount of testosterone produced by existing Leydig cells is under the control of LH, which regulates the expression of 17β-hydroxysteroid dehydrogenase.[128]
The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (see figure to the right).[129] When testosterone levels are low, gonadotropin-releasing hormone (GnRH) is released by the hypothalamus, which in turn stimulates the pituitary gland to release FSH and LH. These latter two hormones stimulate the testis to synthesize testosterone. Finally, increasing levels of testosterone through a negative feedback loop act on the hypothalamus and pituitary to inhibit the release of GnRH and FSH/LH, respectively.
Factors affecting testosterone levels may include:
Age: Testosterone levels gradually reduce as men age.[130][131] This effect is sometimes referred to as andropause or late-onset hypogonadism.[132]
Exercise: Resistance training increases testosterone levels,[133] however, in older men, that increase can be avoided by protein ingestion.[134] Endurance training in men may lead to lower testosterone levels.[135]
Nutrients: Vitamin A deficiency may lead to sub-optimal plasma testosterone levels.[136] The secosteroid vitamin D in levels of 400–1000 IU/d (10–25 µg/d) raises testosterone levels.[137] Zinc deficiency lowers testosterone levels[138] but over-supplementation has no effect on serum testosterone.[139]
Weight loss: Reduction in weight may result in an increase in testosterone levels. Fat cells synthesize the enzyme aromatase, which converts testosterone, the male sex hormone, into estradiol, the female sex hormone.[140] However no clear association between body mass index and testosterone levels has been found.[141]
Miscellaneous: Sleep: (REM sleep) increases nocturnal testosterone levels.[142] Behavior: Dominance challenges can, in some cases, stimulate increased testosterone release in men.[143] Drugs: Natural or man-made antiandrogens including spearmint tea reduce testosterone levels.[144][145][146] Licorice can decrease the production of testosterone and this effect is greater in females.[147]
Distribution[edit]
The plasma protein binding of testosterone is 98.0 to 98.5%, with 1.5 to 2.0% free or unbound.[148] It is bound 65% to sex hormone-binding globulin (SHBG) and 33% bound weakly to albumin.[149]
Plasma protein binding of testosterone and dihydrotestosterone show
Metabolism[edit]
vte Testosterone metabolism in humans
Testosterone structures
The image above contains clickable linksTestosterone metabolism in humans. Conjugation (sulfation and glucuronidation) occurs both with testosterone and with all of the other steroids that have one or more available hydroxyl (-OH) groups in this diagram.
Both testosterone and 5α-DHT are metabolized mainly in the liver.[1][151] Approximately 50% of testosterone is metabolized via conjugation into testosterone glucuronide and to a lesser extent testosterone sulfate by glucuronosyltransferases and sulfotransferases, respectively.[1] An additional 40% of testosterone is metabolized in equal proportions into the 17-ketosteroids androsterone and etiocholanolone via the combined actions of 5α- and 5β-reductases, 3α-hydroxysteroid dehydrogenase, and 17β-HSD, in that order.[1][151][152] Androsterone and etiocholanolone are then glucuronidated and to a lesser extent sulfated similarly to testosterone.[1][151] The conjugates of testosterone and its hepatic metabolites are released from the liver into circulation and excreted in the urine and bile.[1][151][152] Only a small fraction (2%) of testosterone is excreted unchanged in the urine.[151]
In the hepatic 17-ketosteroid pathway of testosterone metabolism, testosterone is converted in the liver by 5α-reductase and 5β-reductase into 5α-DHT and the inactive 5β-DHT, respectively.[1][151] Then, 5α-DHT and 5β-DHT are converted by 3α-HSD into 3α-androstanediol and 3α-etiocholanediol, respectively.[1][151] Subsequently, 3α-androstanediol and 3α-etiocholanediol are converted by 17β-HSD into androsterone and etiocholanolone, which is followed by their conjugation and excretion.[1][151] 3β-Androstanediol and 3β-etiocholanediol can also be formed in this pathway when 5α-DHT and 5β-DHT are acted upon by 3β-HSD instead of 3α-HSD, respectively, and they can then be transformed into epiandrosterone and epietiocholanolone, respectively.[153][154] A small portion of approximately 3% of testosterone is reversibly converted in the liver into androstenedione by 17β-HSD.[152]
In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6.[155] 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations.[155] The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism.[155] In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites.[155][156] Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.[155]
Two of the immediate metabolites of testosterone, 5α-DHT and estradiol, are biologically important and can be formed both in the liver and in extrahepatic tissues.[151] Approximately 5 to 7% of testosterone is converted by 5α-reductase into 5α-DHT, with circulating levels of 5α-DHT about 10% of those of testosterone, and approximately 0.3% of testosterone is converted into estradiol by aromatase.[2][151][157][158] 5α-Reductase is highly expressed in the male reproductive organs (including the prostate gland, seminal vesicles, and epididymides),[159] skin, hair follicles, and brain[160] and aromatase is highly expressed in adipose tissue, bone, and the brain.[161][162] As much as 90% of testosterone is converted into 5α-DHT in so-called androgenic tissues with high 5α-reductase expression,[152] and due to the several-fold greater potency of 5α-DHT as an AR agonist relative to testosterone,[163] it has been estimated that the effects of testosterone are potentiated 2- to 3-fold in such tissues.[164]
Levels[edit]
Total levels of testosterone in the body are 264 to 916 ng/dL in men age 19 to 39 years,[165] while mean testosterone levels in adult men have been reported as 630 ng/dL.[166] Levels of testosterone in men decline with age.[165] In women, mean levels of total testosterone have been reported to be 32.6 ng/dL.[167][168] In women with hyperandrogenism, mean levels of total testosterone have been reported to be 62.1 ng/dL.[167][168]
Testosterone levels in males and females show
Total testosterone levels in males throughout life show
Reference ranges for blood tests, showing adult male testosterone levels in light blue at center-left.
Measurement[edit]
Testosterone’s bioavailable concentration is commonly determined using the Vermeulen calculation or more precisely using the modified Vermeulen method,[174][175] which considers the dimeric form of sex-hormone-binding-globulin.[176]
Both methods use chemical equilibrium to derive the concentration of bioavailable testosterone: in circulation testosterone has two major binding partners, albumin (weakly bound) and sex-hormone-binding-globulin (strongly bound). These methods are described in detail in the accompanying figure.
Dimeric sex-hormone-binding-globulin with its testosterone ligands
Two methods for determining concentration of bioavailable testosterone.
History[edit]
A testicular action was linked to circulating blood fractions – now understood to be a family of androgenic hormones – in the early work on castration and testicular transplantation in fowl by Arnold Adolph Berthold (1803–1861).[177] Research on the action of testosterone received a brief boost in 1889, when the Harvard professor Charles-Édouard Brown-Séquard (1817–1894), then in Paris, self-injected subcutaneously a "rejuvenating elixir" consisting of an extract of dog and guinea pig testicle. He reported in The Lancet that his vigor and feeling of well-being were markedly restored but the effects were transient,[178] and Brown-Séquard's hopes for the compound were dashed. Suffering the ridicule of his colleagues, he abandoned his work on the mechanisms and effects of androgens in human beings.
In 1927, the University of Chicago's Professor of Physiologic Chemistry, Fred C. Koch, established easy access to a large source of bovine testicles — the Chicago stockyards — and recruited students willing to endure the tedious work of extracting their isolates. In that year, Koch and his student, Lemuel McGee, derived 20 mg of a substance from a supply of 40 pounds of bovine testicles that, when administered to castrated roosters, pigs and rats, remasculinized them.[179] The group of Ernst Laqueur at the University of Amsterdam purified testosterone from bovine testicles in a similar manner in 1934, but isolation of the hormone from animal tissues in amounts permitting serious study in humans was not feasible until three European pharmaceutical giants—Schering (Berlin, Germany), Organon (Oss, Netherlands) and Ciba (Basel, Switzerland)—began full-scale steroid research and development programs in the 1930s.
Nobel Prize winner, Leopold Ruzicka of Ciba, a pharmaceutical industry giant that synthesized testosterone.
The Organon group in the Netherlands were the first to isolate the hormone, identified in a May 1935 paper "On Crystalline Male Hormone from Testicles (Testosterone)".[180] They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The structure was worked out by Schering's Adolf Butenandt, at the Chemisches Institut of Technical University in Gdańsk.[181][182]
The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[183] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[184] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[182][185] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.
The partial synthesis in the 1930s of abundant, potent testosterone esters permitted the characterization of the hormone's effects, so that Kochakian and Murlin (1936) were able to show that testosterone raised nitrogen retention (a mechanism central to anabolism) in the dog, after which Allan Kenyon's group[186] was able to demonstrate both anabolic and androgenic effects of testosterone propionate in eunuchoidal men, boys, and women. The period of the early 1930s to the 1950s has been called "The Golden Age of Steroid Chemistry",[187] and work during this period progressed quickly. Research in this golden age proved that this newly synthesized compound—testosterone—or rather family of compounds (for many derivatives were developed from 1940 to 1960), was a potent multiplier of muscle, strength, and well-being.[188]
Other animals[edit]
Testosterone is observed in most vertebrates. Testosterone and the classical nuclear androgen receptor first appeared in gnathostomes (jawed vertebrates).[189] Agnathans (jawless vertebrates) such as lampreys do not produce testosterone but instead use androstenedione as a male sex hormone.[190] Fish make a slightly different form called 11-ketotestosterone.[191] Its counterpart in insects is ecdysone.[192] The presence of these ubiquitous steroids in a wide range of animals suggest that sex hormones have an ancient evolutionary history.[193]
I liked the way that “spinal cord” was obscured behind the stair well - that will get on someone's nerves!
Choice consists of the mental process of judging the merits of multiple options and selecting one of them. While a choice can be made between imagined options ("what would I do if ...?"), often a choice is made between real options, and followed by the corresponding action. For example, a route for a journey is chosen based on the preference of arriving at a given destination as soon as possible. The preferred (and therefore chosen) route is then derived from information about how long each of the possible routes take. This can be done by a route planner. If the preference is more complex, such as involving the scenery of the route, cognition and feeling are more intertwined, and the choice is less easy to delegate to a computer program or assistant.
No matter what may happen, we can choose to live in light. Light, for me, is awareness of truth. Truth is that which happens naturally without being altered; without being altered by perceptual distortions, intentional twisting, or selfish manipulation. There are things and beings that live continuously within the light of truth, because they do not have the human ego to interfere with its presence. The human being, because of its cognition and ego, is the only animate or inanimate being on the planet capable of tampering with truth. We have the choice to accept it, hold on to it, and live according to it; or not. Gandhi believed that truth is so quintessentially important that, toward the end of his life, he said that he has grown to realize that the only real god is truth. He created a word, satyagraha, which literally means “holding on to truth,” and suggested that doing this (holding on to truth) is the true path to peace.
-K. & J.
Truth is beauty (inspired by Burning Man).
“The worrying view coming through is that students are lacking in reflective awareness...Technology makes it easy for them to collate information, but not to analyse and understand it. Much of the evidence suggests that what is going on out there is quite superficial.”
Rose Luckin, Professor of Learner- Centred Design at the London Knowledge Lab on a current study examining the internet's impact on pupils' critical and meta-cognitive skills | Times Online
women.timesonline.co.uk/tol/life_and_style/women/families...
Background image courtesy of: www.flickr.com/photos/steelcityhobbies/1084984228. This citation appears in the top left of the image.
Professor Daniel C. Dennett gave two talks in the Netherlands. The first was "The Tempting Mistakes of Cognition Research" on April 23rd 2008 in the Science center NEMO in celebration of the the ‘KNAW-advies: Van moleculen tot mensen'. The second was "From Animal to Person: How cultural evolution builds human minds" on April 24th in the 'Academisch Medisch Centrum (AMC) This photo was taken at the first talk.
The fundamental attribution error describes the tendency to over-value dispositional or personality-based explanations for behavior while under-valuing situational explanations. The fundamental attribution error is most visible when people explain and assume the behavior of others.
The core process assumptions of attitude construction models are mainstays of social cognition research and are not controversial—as long as we talk about “judgment.” Once the particular judgment made can be thought of as a person’s “attitude,” however, construal assumptions elicit discomfort, presumably because they dispense with the intuitively appealing attitude concept.
A Haiku Note:
~~~~~~~~~~~~~~~~~
Life is but a dream
not really reality
it's an illusion
~~~~~~~~~~~~~~~~~
"You too shall pass away.
Knowing this, how can you quarrel?"
~ The Buddha ~
~ (0000 1011) ~
::::::::::: 0B :::::::::::
=====: 11 :=====
The Noble Eightfold Path describes the way to the end of suffering, as it was laid out by Siddhartha Gautama. It is a practical guideline to ethical and mental development with the goal of freeing the individual from attachments and delusions; and it finally leads to understanding the truth about all things. Together with the Four Noble Truths it constitutes the gist of Buddhism. Great emphasis is put on the practical aspect, because it is only through practice that one can attain a higher level of existence and finally reach Nirvana. The eight aspects of the path are not to be understood as a sequence of single steps, instead they are highly interdependent principles that have to be seen in relationship with each other.
1. Right View
Right view is the beginning and the end of the path, it simply means to see and to understand things as they really are and to realise the Four Noble Truth. As such, right view is the cognitive aspect of wisdom. It means to see things through, to grasp the impermanent and imperfect nature of worldly objects and ideas, and to understand the law of karma and karmic conditioning. Right view is not necessarily an intellectual capacity, just as wisdom is not just a matter of intelligence. Instead, right view is attained, sustained, and enhanced through all capacities of mind. It begins with the intuitive insight that all beings are subject to suffering and it ends with complete understanding of the true nature of all things. Since our view of the world forms our thoughts and our actions, right view yields right thoughts and right actions.
2. Right Intention
While right view refers to the cognitive aspect of wisdom, right intention refers to the volitional aspect, i.e. the kind of mental energy that controls our actions. Right intention can be described best as commitment to ethical and mental self-improvement. Buddha distinguishes three types of right intentions: 1. the intention of renunciation, which means resistance to the pull of desire, 2. the intention of good will, meaning resistance to feelings of anger and aversion, and 3. the intention of harmlessness, meaning not to think or act cruelly, violently, or aggressively, and to develop compassion.
3. Right Speech
Right speech is the first principle of ethical conduct in the eightfold path. Ethical conduct is viewed as a guideline to moral discipline, which supports the other principles of the path. This aspect is not self-sufficient, however, essential, because mental purification can only be achieved through the cultivation of ethical conduct. The importance of speech in the context of Buddhist ethics is obvious: words can break or save lives, make enemies or friends, start war or create peace. Buddha explained right speech as follows: 1. to abstain from false speech, especially not to tell deliberate lies and not to speak deceitfully, 2. to abstain from slanderous speech and not to use words maliciously against others, 3. to abstain from harsh words that offend or hurt others, and 4. to abstain from idle chatter that lacks purpose or depth. Positively phrased, this means to tell the truth, to speak friendly, warm, and gently and to talk only when necessary.
4. Right Action
The second ethical principle, right action, involves the body as natural means of expression, as it refers to deeds that involve bodily actions. Unwholesome actions lead to unsound states of mind, while wholesome actions lead to sound states of mind. Again, the principle is explained in terms of abstinence: right action means 1. to abstain from harming sentient beings, especially to abstain from taking life (including suicide) and doing harm intentionally or delinquently, 2. to abstain from taking what is not given, which includes stealing, robbery, fraud, deceitfulness, and dishonesty, and 3. to abstain from sexual misconduct. Positively formulated, right action means to act kindly and compassionately, to be honest, to respect the belongings of others, and to keep sexual relationships harmless to others. Further details regarding the concrete meaning of right action can be found in the Precepts.
5. Right Livelihood
Right livelihood means that one should earn one's living in a righteous way and that wealth should be gained legally and peacefully. The Buddha mentions four specific activities that harm other beings and that one should avoid for this reason: 1. dealing in weapons, 2. dealing in living beings (including raising animals for slaughter as well as slave trade and prostitution), 3. working in meat production and butchery, and 4. selling intoxicants and poisons, such as alcohol and drugs. Furthermore any other occupation that would violate the principles of right speech and right action should be avoided.
6. Right Effort
Right effort can be seen as a prerequisite for the other principles of the path. Without effort, which is in itself an act of will, nothing can be achieved, whereas misguided effort distracts the mind from its task, and confusion will be the consequence. Mental energy is the force behind right effort; it can occur in either wholesome or unwholesome states. The same type of energy that fuels desire, envy, aggression, and violence can on the other side fuel self-discipline, honesty, benevolence, and kindness. Right effort is detailed in four types of endeavours that rank in ascending order of perfection: 1. to prevent the arising of unarisen unwholesome states, 2. to abandon unwholesome states that have already arisen, 3. to arouse wholesome states that have not yet arisen, and 4. to maintain and perfect wholesome states already arisen.
7. Right Mindfulness
Right mindfulness is the controlled and perfected faculty of cognition. It is the mental ability to see things as they are, with clear consciousness. Usually, the cognitive process begins with an impression induced by perception, or by a thought, but then it does not stay with the mere impression. Instead, we almost always conceptualise sense impressions and thoughts immediately. We interpret them and set them in relation to other thoughts and experiences, which naturally go beyond the facticity of the original impression. The mind then posits concepts, joins concepts into constructs, and weaves those constructs into complex interpretative schemes. All this happens only half consciously, and as a result we often see things obscured. Right mindfulness is anchored in clear perception and it penetrates impressions without getting carried away. Right mindfulness enables us to be aware of the process of conceptualisation in a way that we actively observe and control the way our thoughts go. Buddha accounted for this as the four foundations of mindfulness: 1. contemplation of the body, 2. contemplation of feeling (repulsive, attractive, or neutral), 3. contemplation of the state of mind, and 4. contemplation of the phenomena.
8. Right Concentration
The eighth principle of the path, right concentration, refers to the development of a mental force that occurs in natural consciousness, although at a relatively low level of intensity, namely concentration. Concentration in this context is described as one-pointedness of mind, meaning a state where all mental faculties are unified and directed onto one particular object. Right concentration for the purpose of the eightfold path means wholesome concentration, i.e. concentration on wholesome thoughts and actions. The Buddhist method of choice to develop right concentration is through the practice of meditation. The meditating mind focuses on a selected object. It first directs itself onto it, then sustains concentration, and finally intensifies concentration step by step. Through this practice it becomes natural to apply elevated levels of concentration also in everyday situations.
People orient to information consistent with their attitudes and away from evidence that contradicts them.
(Fazio, 1986)
CC image courtesy of: www.flickr.com/photos/photograham/294717421/
Exposure to ambiguous or mixed information can intensify opinions on a matter, not refine them.
(Khan & Lao, 1996)
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Writing a book here: open.spotify.com/show/3mMrq70ofFvPputOjQIiGU?si=kwclM6f8Q...
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Found this statue in "Ross Dress for Less" store near my house, and painted it white over a black color of the resin.
Researched it carefully because it looks like Parvati - but clearly, it is Prajnaparamita because of the dharmachakra mudra - a symbol of Lord Buddha turning the holy wheel of the Dharma - the wheel of the law - that which is firm.
It has a kind of meditative grace to it.
Heart Sutra
Avalokitesvara Bodhisattva
when practicing deeply the Prajna Paramita
perceives that all five skandhas are empty
and is saved from all suffering and distress.
Shariputra,
form does not differ from emptiness,
emptiness does not differ from form.
That which is form is emptiness,
that which is emptiness form.
The same is true of feelings,
perceptions, impulses, consciousness.
Shariputra,
all dharmas are marked with emptiness;
they do not appear or disappear,
are not tainted or pure,
do not increase or decrease.
Therefore, in emptiness no form, no feelings,
perceptions, impulses, consciousness.
No eyes, no ears, no nose, no tongue, no body, no mind; no color, no sound, no smell, no taste, no touch,
no object of mind;
no realm of eyes
and so forth until no realm of mind consciousness.
No ignorance and also no extinction of it,
and so forth until no old age and death
and also no extinction of them.
No suffering, no origination,
no stopping, no path, no cognition,
also no attainment with nothing to attain.
The Bodhisattva depends on Prajna Paramita
and the mind is no hindrance;
without any hindrance no fears exist.
Far apart from every perverted view one dwells in Nirvana. In the three worlds
all Buddhas depend on Prajna Paramita
and attain Anuttara Samyak Sambodhi.
Therefore know that Prajna Paramita
is the great transcendent mantra,
is the great bright mantra,
is the utmost mantra,
is the supreme mantra
which is able to relieve all suffering
and is true, not false.
So proclaim the Prajna Paramita mantra,
proclaim the mantra which says:
gate gate paragate parasamgate bodhi svaha
gate gate paragate parasamgate bodhi svaha
gate gate paragate parasamgate bodhi svaha.
般若心経/Heart Sutra (Japanese)
ma ka han nya ha ra mi ta shin gyo
摩訶般若波羅蜜多心経
kan ji zai bo sa gyo jin han nya ha ra mi ta ji
観自在菩薩 行深般若波羅蜜多時
sho ken go on kai ku do is-sai ku yaku
照見五蘊皆空 度一切苦厄
sha ri shi shiki fu i ku ku fu i shiki
舍利子 色不異空 空不異色
shiki soku ze ku ku soku ze shiki
色即是空 空即是色
ju so gyo shiki yaku bu nyo ze sha ri shi
受想行識亦復如是 舍利子
ze sho ho ku so fu sho fu metsu
是諸法空相 不生不滅
fu ku fu jo fu zo fu gen ze ko ku chu mu shiki
不垢不浄 不増不減 是故空中 無色
mu ju so gyo shiki mu gen ni bi ze-shin ni
無受想行識 無眼耳鼻舌身意
mu shiki sho ko mi soku ho mu gen kai
無色声香味触法 無眼界
nai shi mu i shiki kai mu mu myo
乃至無意識界 無無明
yaku mu mu myo jin nai shi mu ro shi
亦無無明尽 乃至無老死
yaku mu ro shi jin mu ku shu metsu do
亦無老死尽 無苦集滅道
mu chi yaku mu toku I mu sho toku ko
無智亦無得 以無所得故
bo dai sat-ta e han nya ha ra mi ta ko
菩提薩埵 依般若波羅蜜多故
shin mu kei ge mu ke ge ko
心無罣礙 無罣礙故
mu u ku fu on ri is-sai ten do mu so
無有恐怖 遠離一切顛倒夢想
ku gyo ne han san ze sho butsu
究竟涅槃 三世諸仏
e han-nya ha ra mi ta ko
依般若波羅蜜多故
toku a noku ta ra san myaku san bo dai
得阿耨多羅三藐三菩提
ko chi hannya ha ra mi ta
故知般若波羅蜜多
ze dai jin shu ze dai myo shu
是大神呪 是大明呪
ze mu jo shu ze mu to do shu
是無上呪 是無等等呪
no jo is-sai ku shin jitsu fu ko
能除一切苦 真実不虚
ko setsu han nya hara mi ta shu
故説般若波羅蜜多呪
soku setsu shu watsu
即説呪曰
gya tei gya tei hara gya tei hara so gya tei
羯諦羯諦 波羅羯諦 波羅僧羯諦
bo ji so wa ka hannya shin gyo
菩提薩婆訶 般若心経
Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans (family Alligatoridae), the gharial and false gharial (family Gavialidae) among other extinct taxa.
Although they appear similar, crocodiles, alligators and the gharial belong to separate biological families. The gharial, with its narrow snout, is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head, with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is that the upper and lower jaws of the crocodiles are the same width, and the teeth in the lower jaw fall along the edge or outside the upper jaw when the mouth is closed; therefore, all teeth are visible, unlike an alligator, which possesses in the upper jaw small depressions into which the lower teeth fit. Also, when the crocodile's mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the protruding tooth is the most reliable feature to define the species' family. Crocodiles have more webbing on the toes of the hind feet and can better tolerate saltwater due to specialized salt glands for filtering out salt, which are present, but non-functioning, in alligators. Another trait that separates crocodiles from other crocodilians is their much higher levels of aggression.
Crocodile size, morphology, behaviour and ecology differ somewhat among species. However, they have many similarities in these areas as well. All crocodiles are semiaquatic and tend to congregate in freshwater habitats such as rivers, lakes, wetlands and sometimes in brackish water and saltwater. They are carnivorous animals, feeding mostly on vertebrates such as fish, reptiles, birds and mammals, and sometimes on invertebrates such as molluscs and crustaceans, depending on species and age. All crocodiles are tropical species that, unlike alligators, are very sensitive to cold. They separated from other crocodilians during the Eocene epoch, about 55 million years ago. Many species are at the risk of extinction, some being classified as critically endangered.
Etymology
The word crocodile comes from the Ancient Greek krokódilos (κροκόδιλος) meaning 'lizard', used in the phrase ho krokódilos tou potamoú, "the lizard of the (Nile) river". There are several variant Greek forms of the word attested, including the later form krokódeilos (κροκόδειλος) found cited in many English reference works. In the Koine Greek of Roman times, krokodilos and krokodeilos would have been pronounced identically, and either or both may be the source of the Latinized form crocodīlus used by the ancient Romans. It has been suggested, but it is not certain that the word crocodilos or crocodeilos is a compound of krokè ('pebbles'), and drilos/dreilos ('worm'), although drilos is only attested as a colloquial term for 'penis'. It is ascribed to Herodotus, and supposedly describes the basking habits of the Egyptian crocodile.
The form crocodrillus is attested in Medieval Latin. It is not clear whether this is a medieval corruption or derives from alternative Greco-Latin forms (late Greek corcodrillos and corcodrillion are attested). A (further) corrupted form cocodrille is found in Old French and was borrowed into Middle English as cocodril(le). The Modern English form crocodile was adapted directly from the Classical Latin crocodīlus in the 16th century, replacing the earlier form. The use of -y- in the scientific name Crocodylus (and forms derived from it) is a corruption introduced by Laurenti (1768).
Species
Species nameImageDistributionDescription/Comments
American crocodile (Crocodylus acutus)Throughout the Caribbean Basin, including many of the Caribbean islands and South Florida.A larger sized species, with a greyish colour and a prominent V-shaped snout. Prefers brackish water, but also inhabits lower stretches of rivers and true marine environments. This is one of the rare species that exhibits regular sea-going behaviour, which explains the great distribution throughout the Caribbean. It is also found in hypersaline lakes such as Lago Enriquillo, in the Dominican Republic, which has one of the largest populations of this species. Diet consists mostly of aquatic and terrestrial vertebrates. Classified as Vulnerable, but certain local populations under greater threat.
Hall's New Guinea crocodile (Crocodylus halli)The island of New Guinea, south of the New Guinea HighlandsA smaller species that closely resembles and was long classified under the New Guinea crocodile, which it is now considered to be genetically distinct from. It lives south of the mountain barrier that divides the two species' ranges. It can be physically distinguished from the New Guinea crocodile by its shorter maxilla and enlarged postcranial elements. Cranial elements can still widely vary within the species, with populations from Lake Murray having much wider heads than those from the Aramia River.
Orinoco crocodile (Crocodylus intermedius)Colombia and VenezuelaThis is a large species with a relatively elongated snout and a pale tan coloration with scattered dark brown markings. Lives primarily in the Orinoco Basin. Despite having a rather narrow snout, preys on a wide variety of vertebrates, including large mammals. It is a Critically Endangered species.
Freshwater crocodile (Crocodylus johnstoni)Northern AustraliaA smaller species with a narrow and elongated snout. It has light brown coloration with darker bands on body and tail. Lives in rivers with considerable distance from the sea, to avoid confrontations with saltwater crocodiles. Feeds mostly on fish and other small vertebrates.
Philippine crocodile (Crocodylus mindorensis)Endemic to the PhilippinesThis is a relatively small species with a rather broader snout. It has heavy dorsal armour and a golden-brown colour that darkens as the animal matures. Prefers freshwater habitats and feeds on a variety of small to medium sized vertebrates. This species is Critically Endangered and the most severely threatened species of crocodile.
Morelet's crocodile (Crocodylus moreletii)Atlantic regions of Mexico, Belize and GuatemalaA small to medium sized crocodile with a rather broad snout. It has a dark greyish-brown colour and is found in mostly various freshwater habitats. Feeds on mammals, birds and reptiles. It is listed as Least Concern.
Nile crocodile (Crocodylus niloticus)Sub-saharan AfricaA large and aggressive species with a broad snout, especially in older animals. It has a dark bronze coloration and darkens as the animal matures. Lives in a variety of freshwater habitats but is also found in brackish water. It is an apex predator that is capable of taking a wide array of African vertebrates, including large ungulates and other predators. This species is listed as Least Concern.
New Guinea crocodile (Crocodylus novaeguineae)The island of New Guinea, north of the New Guinea HighlandsA smaller species of crocodile with a grey-brown colour and dark brown to black markings on the tail. The young have a narrower V-shaped snout that becomes wider as the animal matures. Prefers freshwater habitats, even though is tolerant to salt water, in order to avoid competition and predation by the saltwater crocodile. This species feeds on small to mid-sized vertebrates.
Mugger crocodile (Crocodylus palustris)The Indian subcontinent and surrounding countriesThis is a modest sized crocodile with a very broad snout and an alligator-like appearance. It has dark-grey to brown coloration. Enlarged scutes around the neck make it a heavily armoured species. Prefers slow moving rivers, swamps and lakes. It can also be found in coastal swamps but avoids areas populated by saltwater crocodiles. Feeds on a wide array of vertebrates.
Saltwater crocodile (Crocodylus porosus)Throughout Southeast Asia, Northern Australia and surrounding watersThe largest living reptile and most aggressive of all crocodiles. It is a big-headed species and has a relatively broad snout, especially when older. The coloration is pale yellow with black stripes when young but dark greenish-drab coloured as adults. Lives in brackish and marine environments as well as lower stretches of rivers. This species has the greatest distribution of all crocodiles. Tagged specimens showed long-distance marine travelling behaviour. It is the apex predator throughout its range and preys on virtually any animal within its reach. It is classified as Least Concern with several populations under greater risk.
Borneo crocodile (Crocodylus raninus)Island of Borneo in Southeast AsiaA freshwater species of crocodile that has been considered a synonym of the saltwater crocodile.
Cuban crocodile (Crocodylus rhombifer)Found only in the Zapata Swamp and Isle of Youth of CubaIt is a small but extremely aggressive species of crocodile that prefers freshwater swamps. The coloration is vibrant even as adults and the scales have a "pebbled" appearance. It is a relatively terrestrial species with agile locomotion on land, and sometimes displays terrestrial hunting. The snout is broad with a thick upper-jaw and large teeth. The unique characteristics and fossil record indicates a rather specialized diet in the past, preying on megafauna such as the giant sloth. This species sometimes displays pack-hunting behaviour, which might have been the key to hunting large species in the past, despite its small size.[ Today most prey are small to medium sized vertebrates. It is Critically Endangered, and the remaining wild population is under threat of hybridization.
Siamese crocodile (Crocodylus siamensis)Indonesia, Brunei, East Malaysia and southern IndochinaA fairly small crocodile that prefers freshwater habitats. It has a relatively broad snout and olive-green to dark green coloration. It feeds on a variety of small to mid-sized vertebrates. Listed as Critically Endangered, but might be already extinct in the wild; status is unknown.
West African crocodile (Crocodylus suchus)Western and Central AfricaRecent studies revealed that this is distinct species from the larger Nile crocodile. It has a slightly narrower snout and is much smaller compared to its larger cousin.
Osborn’s dwarf crocodile (Osteolaemus osborni)Western AfricaIt is the smallest of all living crocodiles. It is a heavily armoured species with uniform black coloration in adults, while juveniles have a lighter brown banding. Lives in the tropical forests of Western Africa. Feeds on small vertebrates and large aquatic invertebrates. It is a fairly terrestrial species and exhibits terrestrial hunting, especially at night.
Dwarf crocodile (Osteolaemus tetraspis)Western AfricaIt is the smallest of all living crocodiles. It belongs to its own monotypic genus; however, new studies indicate there might be two or even three distinct species. It is a heavily armoured species with uniform black coloration in adults, while juveniles have a lighter brown banding. Lives in the tropical forests of Western Africa. Feeds on small vertebrates and large aquatic invertebrates. It is a fairly terrestrial species and exhibits terrestrial hunting, especially at night. This species is classified as Vulnerable.
West African slender-snouted crocodile (Mecistops cataphractus)Western AfricaA medium sized species with a narrow and elongated snout. Lives in freshwater habitats within tropical forests of the continent. Feeds mostly on fish but also other small to medium sized vertebrates. It is a Critically Endangered species.
Central African slender-snouted crocodile (Mecistops leptorhynchus)Central AfricaA medium sized species found in watery areas in dense rainforest. Feeds largely on fish. Insufficient conservation data, but was classified as Critically Endangered when lumped with M. cataphractus, although M. leptorhynchus is doing better in its home range.
For information on Tomistoma or false gharial, that is recently not considered as a true crocodile, see False gharial.
Characteristics
A crocodile's physical traits allow it to be a successful predator. Its external morphology is a sign of its aquatic and predatory lifestyle. Its streamlined body enables it to swim swiftly; it also tucks its feet to the side while swimming, making it faster by decreasing water resistance. Crocodiles have webbed feet which, though not used to propel them through the water, allow them to make fast turns and sudden moves in the water or initiate swimming. Webbed feet are an advantage in shallow water, where the animals sometimes move around by walking. Crocodiles have a palatal flap, a rigid tissue at the back of the mouth that blocks the entry of water. The palate has a special path from the nostril to the glottis that bypasses the mouth. The nostrils are closed during submergence.
Like other archosaurs, crocodilians are diapsid, although their post-temporal fenestrae are reduced. The walls of the braincase are bony but lack supratemporal and postfrontal bones. Their tongues are not free, but held in place by a membrane that limits movement; as a result, crocodiles are unable to stick out their tongues. Crocodiles have smooth skin on their bellies and sides, while their dorsal surfaces are armoured with large osteoderms. The armoured skin has scales and is thick and rugged, providing some protection. They are still able to absorb heat through this armour, as a network of small capillaries allows blood through the scales to absorb heat. The osteoderms are highly vascularised and aid in calcium balance, both to neutralize acids while the animal cannot breathe underwater and to provide calcium for eggshell formation. Crocodilian tegument have pores believed to be sensory in function, analogous to the lateral line in fishes. They are particularly seen on their upper and lower jaws. Another possibility is that they are secretory, as they produce an oily substance which appears to flush mud off.
Size
Size greatly varies among species, from the dwarf crocodile to the saltwater crocodile. Species of the dwarf crocodile Osteolaemus grow to an adult size of just 1.5 to 1.9 m (4.9 to 6.2 ft), whereas the saltwater crocodile can grow to sizes over 6 m (20 ft) and weigh over 1,000 kg (2,200 lb). Several other large species can reach over 5.2 m (17 ft) long and weigh over 900 kg (2,000 lb). Crocodilians show pronounced sexual dimorphism, with males growing much larger and more rapidly than females. Despite their large adult sizes, crocodiles start their lives at around 20 cm (7.9 in) long. The largest species of crocodile is the saltwater crocodile, found in eastern India, northern Australia, throughout South-east Asia, and in the surrounding waters.
The brain volume of two adult crocodiles was 5.6 cm3 for a spectacled caiman and 8.5 cm3 for a larger Nile crocodile.
The largest crocodile ever held in captivity is a saltwater–Siamese hybrid named Yai (Thai: ใหญ่, meaning big; born 10 June 1972) at the Samutprakarn Crocodile Farm and Zoo, Thailand. This animal measures 6 m (20 ft) in length and weighs 1,200 kg (2,600 lb).
The longest crocodile captured alive was Lolong, a saltwater crocodile which was measured at 6.17 m (20.2 ft) and weighed at 1,075 kg (2,370 lb) by a National Geographic team in Agusan del Sur Province, Philippines.
Teeth
Crocodiles are polyphyodonts; they are able to replace each of their 80 teeth up to 50 times in their 35- to 75-year lifespan. Next to each full-grown tooth, there is a small replacement tooth and an odontogenic stem cell in the dental lamina in standby that can be activated if required.
Biology and behaviour
Crocodilians are more closely related to birds and dinosaurs than to most animals classified as reptiles, the three families being included in the group Archosauria ('ruling reptiles'). Despite their prehistoric look, crocodiles are among the more biologically complex reptiles. Unlike other reptiles, a crocodile has a cerebral cortex and a four-chambered heart. Crocodilians also have the functional equivalent of a diaphragm by incorporating muscles used for aquatic locomotion into respiration. Salt glands are present in the tongues of crocodiles and they have a pore opening on the surface of the tongue, a trait that separates them from alligators. Salt glands are dysfunctional in Alligatoridae. Their function appears to be similar to that of salt glands in marine turtles. Crocodiles do not have sweat glands and release heat through their mouths. They often sleep with their mouths open and may pant like a dog. Four species of freshwater crocodile climb trees to bask in areas lacking a shoreline.
Senses
Crocodiles have acute senses, an evolutionary advantage that makes them successful predators. The eyes, ears and nostrils are located on top of the head, allowing the crocodile to lie low in the water, almost totally submerged and hidden from prey.
Vision
Crocodiles have very good night vision, and are mostly nocturnal hunters. They use the disadvantage of most prey animals' poor nocturnal vision to their advantage. The light receptors in crocodilians' eyes include cones and numerous rods, so it is assumed all crocodilians can see colours. Crocodiles have vertical-slit shaped pupils, similar to those of domestic cats. One explanation for the evolution of slit pupils is that they exclude light more effectively than a circular pupil, helping to protect the eyes during daylight. On the rear wall of the eye is a tapetum lucidum, which reflects incoming light back onto the retina, thus utilizing the small amount of light available at night to best advantage. In addition to the protection of the upper and lower eyelids, crocodiles have a nictitating membrane (sometimes called a "third eye-lid") that can be drawn over the eye from the inner corner while the lids are open. The eyeball surface is thus protected under the water while a certain degree of vision is still possible.
Olfaction
Crocodilian sense of smell is also very well developed, aiding them to detect prey or animal carcasses that are either on land or in water, from far away. It is possible that crocodiles use olfaction in the egg prior to hatching.
Chemoreception in crocodiles is especially interesting because they hunt in both terrestrial and aquatic surroundings. Crocodiles have only one olfactory chamber and the vomeronasal organ is absent in the adults indicating all olfactory perception is limited to the olfactory system. Behavioural and olfactometer experiments indicate that crocodiles detect both air-borne and water-soluble chemicals and use their olfactory system for hunting. When above water, crocodiles enhance their ability to detect volatile odorants by gular pumping, a rhythmic movement of the floor of the pharynx. Crocodiles close their nostrils when submerged, so olfaction underwater is unlikely. Underwater food detection is presumably gustatory and tactile.
Hearing
Crocodiles can hear well; their tympanic membranes are concealed by flat flaps that may be raised or lowered by muscles.
Touch
The touch sensors, concentrated in crocodile skin, can be thicker than those in human fingerprints. Crocodiles can feel the touch on their skin.
Cranial: The upper and lower jaws are covered with sensory pits, visible as small, black speckles on the skin, the crocodilian version of the lateral line organs seen in fish and many amphibians, though arising from a completely different origin. These pigmented nodules encase bundles of nerve fibers innervated beneath by branches of the trigeminal nerve. They respond to the slightest disturbance in surface water, detecting vibrations and small pressure changes as small as a single drop. This makes it possible for crocodiles to detect prey, danger and intruders, even in total darkness. These sense organs are known as domed pressure receptors (DPRs).
Post-Cranial: While alligators and caimans have DPRs only on their jaws, crocodiles have similar organs on almost every scale on their bodies. The function of the DPRs on the jaws is clear; to catch prey, but it is still not clear what the function is of the organs on the rest of the body. The receptors flatten when exposed to increased osmotic pressure, such as that experienced when swimming in sea water hyperosmotic to the body fluids. When contact between the integument and the surrounding sea water solution is blocked, crocodiles are found to lose their ability to discriminate salinities. It has been proposed that the flattening of the sensory organ in hyperosmotic sea water is sensed by the animal as "touch", but interpreted as chemical information about its surroundings. This might be why in alligators they are absent on the rest of the body.
Hunting and diet
Crocodiles are ambush predators, waiting for fish or land animals to come close, then rushing out to attack. Crocodiles mostly eat fish, amphibians, crustaceans, molluscs, birds, reptiles, and mammals, and they occasionally cannibalize smaller crocodiles. What a crocodile eats varies greatly with species, size and age. From the mostly fish-eating species, like the slender-snouted and freshwater crocodiles, to the larger species like the Nile crocodile and the saltwater crocodile that prey on large mammals, such as buffalo, deer and wild boar, diet shows great diversity. Diet is also greatly affected by the size and age of the individual within the same species. All young crocodiles hunt mostly invertebrates and small fish, gradually moving on to larger prey. Being ectothermic (cold-blooded) predators, they have a very slow metabolism, so they can survive long periods without food. Despite their appearance of being slow, crocodiles have a very fast strike and are top predators in their environment, and various species have been observed attacking and killing other predators such as sharks and big cats. Crocodiles are also known to be aggressive scavengers who feed upon carrion and steal from other predators. Evidence suggests that crocodiles also feed upon fruits, based on the discovery of seeds in stools and stomachs from many subjects as well as accounts of them feeding.
Crocodiles have the most acidic stomach of any vertebrate. They can easily digest bones, hooves and horns. The BBC TV reported that a Nile crocodile that has lurked a long time underwater to catch prey builds up a large oxygen debt. When it has caught and eaten that prey, it closes its right aortic arch and uses its left aortic arch to flush blood loaded with carbon dioxide from its muscles directly to its stomach; the resulting excess acidity in its blood supply makes it much easier for the stomach lining to secrete more stomach acid to quickly dissolve bulks of swallowed prey flesh and bone. Many large crocodilians swallow stones (called gastroliths or stomach stones), which may act as ballast to balance their bodies or assist in crushing food, similar to grit ingested by birds. Herodotus claimed that Nile crocodiles had a symbiotic relationship with certain birds, such as the Egyptian plover, which enter the crocodile's mouth and pick leeches feeding on the crocodile's blood; with no evidence of this interaction actually occurring in any crocodile species, it is most likely mythical or allegorical fiction.
Bite
Since they feed by grabbing and holding onto their prey, they have evolved sharp teeth for piercing and holding onto flesh, and powerful muscles to close the jaws and hold them shut. The teeth are not well-suited to tearing flesh off of large prey items as are the dentition and claws of many mammalian carnivores, the hooked bills and talons of raptorial birds, or the serrated teeth of sharks. However, this is an advantage rather than a disadvantage to the crocodile since the properties of the teeth allow it to hold onto prey with the least possibility of the prey animal escaping. Cutting teeth, combined with the exceptionally high bite force, would pass through flesh easily enough to leave an escape opportunity for prey. The jaws can bite down with immense force, by far the strongest bite of any animal. The force of a large crocodile's bite is more than 5,000 lbf (22,000 N), which was measured in a 5.5 m (18 ft) Nile crocodile, in the field; comparing to 335 lbf (1,490 N) for a Rottweiler, 800 lbf (3,600 N) for a hyena, 2,200 lbf (9,800 N) for an American alligator, and 4,095 lbf (18,220 N) for the largest confirmed great white shark.
A 5.2 m (17 ft) long saltwater crocodile has been confirmed as having the strongest bite force ever recorded for an animal in a laboratory setting. It was able to apply a bite force value of 3,700 lbf (16,000 N), and thus surpassed the previous record of 2,125 lbf (9,450 N) made by a 3.9 m (13 ft) long American alligator. Taking the measurements of several 5.2 m (17 ft) crocodiles as reference, the bite forces of 6-m individuals were estimated at 7,700 lbf (34,000 N). The study, led by Dr. Gregory M. Erickson, also shed light on the larger, extinct species of crocodilians. Since crocodile anatomy has changed only slightly over the last 80 million years, current data on modern crocodilians can be used to estimate the bite force of extinct species. An 11-to-12-metre (36–39 ft) Deinosuchus would apply a force of 23,100 lbf (103,000 N), nearly twice that of the latest, higher bite force estimations of Tyrannosaurus (12,814 lbf (57,000 N)). The extraordinary bite of crocodilians is a result of their anatomy. The space for the jaw muscle in the skull is very large, which is easily visible from the outside as a bulge at each side. The muscle is so stiff, it is almost as hard as bone to touch, as if it were the continuum of the skull. Another trait is that most of the muscle in a crocodile's jaw is arranged for clamping down. Despite the strong muscles to close the jaw, crocodiles have extremely small and weak muscles to open the jaw. Crocodiles can thus be subdued for study or transport by taping their jaws or holding their jaws shut with large rubber bands cut from automobile inner tubes.
Locomotion
Crocodiles can move quickly over short distances, even out of water. The land speed record for a crocodile is 17 km/h (11 mph) measured in a galloping Australian freshwater crocodile. Maximum speed varies between species. Some species can gallop, including Cuban crocodiles, Johnston's crocodiles, New Guinea crocodiles, African dwarf crocodiles, and even small Nile crocodiles. The fastest means by which most species can move is a "belly run", in which the body moves in a snake-like (sinusoidal) fashion, limbs splayed out to either side paddling away frantically while the tail whips to and fro. Crocodiles can reach speeds of 10–11 km/h (6–7 mph) when they "belly run", and often faster if slipping down muddy riverbanks. When a crocodile walks quickly, it holds its legs in a straighter and more upright position under its body, which is called the "high walk". This walk allows a speed of up to 5 km/h.
Crocodiles may possess a homing instinct. In northern Australia, three rogue saltwater crocodiles were relocated 400 km (249 mi) by helicopter, but returned to their original locations within three weeks, based on data obtained from tracking devices attached to them.
Longevity
Measuring crocodile age is unreliable, although several techniques are used to derive a reasonable guess. The most common method is to measure lamellar growth rings in bones and teeth—each ring corresponds to a change in growth rate which typically occurs once a year between dry and wet seasons. Bearing these inaccuracies in mind, it can be safely said that all crocodile species have an average lifespan of at least 30–40 years, and in the case of larger species an average of 60–70 years. The oldest crocodiles appear to be the largest species. C. porosus is estimated to live around 70 years on average, with limited evidence of some individuals exceeding 100 years.
In captivity, some individuals are claimed to have lived for over a century. A male crocodile lived to an estimated age of 110–115 years in a Russian zoo in Yekaterinburg. Named Kolya, he joined the zoo around 1913 to 1915, fully grown, after touring in an animal show, and lived until 1995.[70] A male freshwater crocodile lived to an estimated age of 120–140 years at the Australia Zoo. Known affectionately as "Mr. Freshie", he was rescued around 1970 by Bob Irwin and Steve Irwin, after being shot twice by hunters and losing an eye as a result, and lived until 2010. Crocworld Conservation Centre, in Scottburgh, South Africa, claims to have a male Nile crocodile that was born in 1900. Named Henry, the crocodile is said to have lived in Botswana along the Okavango River, according to centre director Martin Rodrigues.
Social behaviour and vocalization
Crocodiles are the most social of reptiles. Even though they do not form social groups, many species congregate in certain sections of rivers, tolerating each other at times of feeding and basking. Most species are not highly territorial, with the exception of the saltwater crocodile, which is a highly territorial and aggressive species: a mature, male saltwater crocodile will not tolerate any other males at any time of the year, but most other species are more flexible. There is a certain form of hierarchy in crocodiles: the largest and heaviest males are at the top, having access to the best basking site, while females are priority during a group feeding of a big kill or carcass. A good example of the hierarchy in crocodiles would be the case of the Nile crocodile. This species clearly displays all of these behaviours. Studies in this area are not thorough, however, and many species are yet to be studied in greater detail. Mugger crocodiles are also known to show toleration in group feedings and tend to congregate in certain areas. However, males of all species are aggressive towards each other during mating season, to gain access to females.
Crocodiles are also the most vocal of all reptiles, producing a wide variety of sounds during various situations and conditions, depending on species, age, size and sex. Depending on the context, some species can communicate over 20 different messages through vocalizations alone. Some of these vocalizations are made during social communication, especially during territorial displays towards the same sex and courtship with the opposite sex; the common concern being reproduction. Therefore most conspecific vocalization is made during the breeding season, with the exception being year-round territorial behaviour in some species and quarrels during feeding. Crocodiles also produce different distress calls and in aggressive displays to their own kind and other animals; notably other predators during interspecific predatory confrontations over carcasses and terrestrial kills.
Specific vocalisations include —
Chirp: When about to hatch, the young make a "peeping" noise, which encourages the female to excavate the nest. The female then gathers the hatchlings in her mouth and transports them to the water, where they remain in a group for several months, protected by the female[76]
Distress call: A high-pitched call used mostly by younger animals to alert other crocodiles to imminent danger or an animal being attacked.
Threat call: A hissing sound that has also been described as a coughing noise.
Hatching call: Emitted by a female when breeding to alert other crocodiles that she has laid eggs in her nest.
Bellowing: Male crocodiles are especially vociferous. Bellowing choruses occur most often in the spring when breeding groups congregate, but can occur at any time of year. To bellow, males noticeably inflate as they raise the tail and head out of water, slowly waving the tail back and forth. They then puff out the throat and with a closed mouth, begin to vibrate air. Just before bellowing, males project an infrasonic signal at about 10 Hz through the water, which vibrates the ground and nearby objects. These low-frequency vibrations travel great distances through both air and water to advertise the male's presence and are so powerful they result in the water's appearing to "dance".
Reproduction
Crocodiles lay eggs, which are laid in either holes or mound nests, depending on species. A hole nest is usually excavated in sand and a mound nest is usually constructed out of vegetation. Nesting periods range from a few weeks up to six months. Courtship takes place in a series of behavioural interactions that include a variety of snout rubbing and submissive display that can take a long time. Mating always takes place in water, where the pair can be observed mating several times. Females can build or dig several trial nests which appear incomplete and abandoned later. Egg-laying usually takes place at night and about 30–40 minutes. Females are highly protective of their nests and young. The eggs are hard shelled, but translucent at the time of egg-laying. Depending on the species of crocodile, 7 to 95 eggs are laid. Crocodile embryos do not have sex chromosomes, and unlike humans, sex is not determined genetically. Sex is determined by temperature, where at 30 °C (86 °F) or less most hatchlings are females and at 31 °C (88 °F), offspring are of both sexes. A temperature of 32 to 33 °C (90 to 91 °F) gives mostly males whereas above 33 °C (91 °F) in some species continues to give males, but in other species resulting in females, which are sometimes called high-temperature females. Temperature also affects growth and survival rate of the young, which may explain the sexual dimorphism in crocodiles. The average incubation period is around 80 days, and also is dependent on temperature and species that usually ranges from 65 to 95 days. The eggshell structure is very conservative through evolution but there are enough changes to tell different species apart by their eggshell microstructure. Scutes may play a role in calcium storage for eggshell formation.
At the time of hatching, the young start calling within the eggs. They have an egg-tooth at the tip of their snouts, which is developed from the skin, and that helps them pierce out of the shell. Hearing the calls, the female usually excavates the nest and sometimes takes the unhatched eggs in her mouth, slowly rolling the eggs to help the process. The young is usually carried to the water in the mouth. She would then introduce her hatchlings to the water and even feed them. The mother would then take care of her young for over a year before the next mating season. In the absence of the mother crocodile, the father would act in her place to take care of the young. However, even with a sophisticated parental nurturing, young crocodiles have a very high mortality rate due to their vulnerability to predation. A group of hatchlings is called a pod or crèche and may be protected for months.
Cognition
Crocodiles possess some advanced cognitive abilities. They can observe and use patterns of prey behaviour, such as when prey come to the river to drink at the same time each day. Vladimir Dinets of the University of Tennessee, observed that crocodiles use twigs as bait for birds looking for nesting material. They place sticks on their snouts and partly submerge themselves. When the birds swooped in to get the sticks, the crocodiles then catch the birds. Crocodiles only do this in spring nesting seasons of the birds, when there is high demand for sticks to be used for building nests. Vladimir also discovered other similar observations from various scientists, some dating back to the 19th century. Aside from using sticks, crocodiles are also capable of cooperative hunting. Large numbers of crocodiles swim in circles to trap fish and take turns snatching them. In hunting larger prey, crocodiles swarm in, with one holding the prey down as the others rip it apart.
According to a 2015 study, crocodiles engage in all three main types of play behaviour recorded in animals: locomotor play, play with objects and social play. Play with objects is reported most often, but locomotor play such as repeatedly sliding down slopes, and social play such as riding on the backs of other crocodiles is also reported. This behaviour was exhibited with conspecifics and mammals and is apparently not uncommon, though has been difficult to observe and interpret in the past due to obvious dangers of interacting with large carnivores.
Taxonomy and phylogeny
See also: List of crocodilians
Crocodylidae is cladistically defined as a crown group composed of the last common ancestor of the Nile crocodile (Crocodylus niloticus), the Dwarf crocodile (Osteolaemus tetraspis), and all of its descendants. It contains two subfamilies: Crocodylinae and Osteolaeminae. Crocodylinae contains 13-14 living species, as well as 6 extinct species. Osteolaeminae was named by Christopher Brochu in 2003 as a subfamily of Crocodylidae separate from Crocodylinae and contains the two extant genera Osteolaemus and Mecistops, along with several extinct genera. The number of extant species within Osteolaeminae is currently in question.
Subfamily Crocodylinae
Genus Crocodylus
Crocodylus acutus, American crocodile
Crocodylus halli, Hall's New Guinea crocodile found South of the New Guinea Highlands
Crocodylus intermedius, Orinoco crocodile
Crocodylus johnsoni, freshwater crocodile, or Johnstone's crocodile
Crocodylus mindorensis, Philippine crocodile
Crocodylus moreletii, Morelet's crocodile or Mexican crocodile
Crocodylus niloticus, Nile crocodile or African crocodile (the subspecies found in Madagascar is sometimes called the black crocodile)
Crocodylus novaeguineae, New Guinea crocodile found North of the New Guinea Highlands
Crocodylus palustris, mugger, marsh or Indian crocodile
Crocodylus porosus, saltwater crocodile or estuarine crocodile
Crocodylus raninus, the Borneo crocodile, is currently considered to be a synonym of Crocodylus porosus; whether or not it is a distinct species remains unclear.
Crocodylus rhombifer, Cuban crocodile
Crocodylus siamensis, Siamese crocodile (may be extinct in the wild)
Crocodylus suchus, West African crocodile, desert or sacred crocodile
Crocodylus anthropophagus†
Crocodylus checchiai†
Crocodylus falconensis†
Crocodylus palaeindicus†
Crocodylus thorbjarnarsoni†
Genus Voay†
Voay robustus† (formerly Crocodylus robustus)
Subfamily Osteolaeminae
Genus Osteolaemus
Osteolaemus tetraspis, dwarf crocodile (There has been controversy as to whether or not this is actually two species; recent (2010) DNA analysis indicate three distinct species: O. tetraspis, O. osborni and a third, currently unnamed.)
Genus Mecistops
Mecistops cataphractus West African slender-snouted crocodile
Mecistops leptorhynchus Central African slender-snouted crocodile
Genus Brochuchus†
Brochuchus pigotti† (formerly Crocodylus pigotti)
Brochuchus parvidens†
Genus Euthecodon†
Euthecodon nitriae†
Euthecodon brumpti†
Euthecodon arambourgi†
Genus Rimasuchus†
Rimasuchus lloydi† (formerly Crocodylus lloydi)
Phylogeny
Recent molecular studies using DNA sequencing have shown crocodiles to be more closely related to the gavialids rather than to alligators, contrary to prior theories based on morphological studies alone.
Crocodilia
Alligatoridae
Caimaninae
Caiman
Melanosuchus
Paleosuchus
Alligatorinae
Alligator
Longirostres
Crocodylidae
Crocodylus
Mecistops
Osteolaemus
Gavialidae
Gavialis
Tomistoma
Mecistops cataphractus West African slender-snouted crocodile
Euthecodon†
Brochuchus†
Rimasuchus†
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
Crocodylinae
Voay†
Crocodylus
Crocodylus anthropophagus†
Crocodylus thorbjarnarsoni†
Crocodylus palaeindicus†
Crocodylus Tirari Desert†
Crocodylus johnstoni Freshwater crocodile
Crocodylus novaeguineae New Guinea crocodile
Crocodylus mindorensis Philippine crocodile
Crocodylus porosus Saltwater crocodile
Crocodylus siamensis Siamese crocodile
Crocodylus palustris Mugger crocodile
Crocodylus checchiai†
Crocodylus falconensis†
Crocodylus suchus West African crocodile
Crocodylus niloticus Nile crocodile
Crocodylus moreletii Morelet's crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
(crown group)
Crocodylidae
Osteolaeminae
Rimasuchus lloydi†
Voay robustus†
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
"Crocodylus" gariepensis†
Brochuchus parvidens†
Brochuchus pigotti†
Euthecodon arambourgi†
Euthecodon brumpti†
Crocodylinae
Mecistops cataphractus West African slender-snouted crocodile
Crocodylus thorbjarnarsoni†
Crocodylus anthropophagus†
Crocodylus niloticus Nile crocodile
Crocodylus checchiai†
Crocodylus moreletii Morelet's crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus palaeindicus†
Crocodylus palustris Mugger crocodile
Crocodylus ossifragus†
Crocodylus siamensis Siamese crocodile
Crocodylus mindorensis Philippine crocodile
Crocodylus johnstoni Freshwater crocodile
Crocodylus porosus Saltwater crocodile
Crocodylus raninus Borneo crocodile
Crocodylus novaeguineae New Guinea crocodile
Paleoafrican CrocodylusNeotropical CrocodylusIndo-Pacific Crocodylus
Relationship with humans
Danger to humans
Main article: Crocodile attacks
The larger species of crocodiles are very dangerous to humans, mainly because of their ability to strike before the person can react. The saltwater crocodile and Nile crocodile are the most dangerous, killing hundreds of people each year in parts of Southeast Asia and Africa. The mugger crocodile and American crocodile are also dangerous to humans.
Crocodile products
Further information: Crocodile farm and Crocodile skin
Crocodiles are protected in many parts of the world, but are also farmed commercially. Their hides are tanned and used to make leather goods such as shoes and handbags; crocodile meat is also considered a delicacy. The most commonly farmed species are the saltwater and Nile crocodiles, while a hybrid of the saltwater and the rare Siamese crocodile is also bred in Asian farms. Farming has resulted in an increase in the saltwater crocodile population in Australia, as eggs are usually harvested from the wild, so landowners have an incentive to conserve their habitat. Crocodile leather can be made into goods such as wallets, briefcases, purses, handbags, belts, hats, and shoes. Crocodile oil has been used for various purposes. Crocodiles were eaten by Vietnamese while they were taboo and off limits for Chinese. Vietnamese women who married Chinese men adopted the Chinese taboo.
Crocodile meat is consumed in some countries, such as Australia, Ethiopia, Thailand, South Africa, China, and Cuba (in pickled form). It is also occasionally eaten as an "exotic" delicacy in the western world. Cuts of meat include backstrap and tail fillet.
Due to high demand for crocodile products, TRAFFIC states that 1,418,487 Nile Crocodile skins were exported from Africa between 2006 and 2015.
Crocodile hunting and conservation
Aboriginal Australians harvested eggs and hunted crocodiles in a sustainable way for many thousands of years. The Brinkin people (aka Marrithiyal) of the Daly River in the Northern Territory (NT) used harpoons and bamboo, and even their own hands to capture crocodiles for food. After settlement of northern Australia, in the late-19th and early 20th centuries, non-Indigenous people killed individual crocodiles, mostly by locals to protect the population, or novelty-seeking visitors, or just opportunistically, so numbers were not noticeably reduced. From the 1930s, commercial hunting began, with Aboriginal people often employed to kill the crocodiles using traditional methods. From the 1940s to the 1960s, hunting began on a larger scale using .303 rifles. They were hunted for leather, with the skins shipped to plants in capital cities. Western Australia banned hunting freshwater crocodiles in 1962 and saltwater crocodiles in 1970, while NT bans were brought in 1964 and 1971; Queensland did not pass such legislation. The federal government later banned the export of crocodile skins, which brought commercial hunting to an end in Queensland. They have been a protected species since the 1970s, when numbers were down to approximately 3,000 in the NT at the lowest estimate. In 2021, after several attacks on humans by the "salties" and an estimated population of around 200,000 had been reached, Queensland politician Bob Katter called for the reintroduction of hunting.
In religion and mythology
Further information: Crocodilia § Cultural_depictions
Crocodiles have appeared in various forms in religions across the world. Ancient Egypt had Sobek, the crocodile-headed god, with his cult-city Crocodilopolis, as well as Taweret, the goddess of childbirth and fertility, with the back and tail of a crocodile. The Jukun shrine in the Wukari Federation, Nigeria is dedicated to crocodiles in thanks for their aid during migration. In Madagascar various peoples such as the Sakalava and Antandroy see crocodiles as ancestor spirits and under local fady often offer them food; in the case of the latter at least a crocodile features prominently as an ancestor deity.
Crocodiles appear in different forms in Hinduism. Varuna, a Vedic and Hindu god, rides a part-crocodile makara; his consort Varuni rides a crocodile.[88] Similarly the goddess personifications of the Ganga and Yamuna rivers are often depicted as riding crocodiles. Also in India, in Goa, crocodile worship is practised, including the annual Mannge Thapnee ceremony.
Sikh warriors known as nihang also have connections with crocodiles. Nihang may come from the Persian word for a mythical sea creature (Persian: نهنگ). The term owes its origin to Mughal historians, who compared the ferocity of the Akali with that of crocodiles. The meaning of Akali in Sikhism however, is the immortal army of Akal (god).
In Latin America, Cipactli was the giant earth crocodile of the Aztec and other Nahua peoples.
Fighting shark and crocodile, the emblem of Surabaya
The name of Surabaya,Indonesia, is locally believed to be derived from the words "suro" (shark) and "boyo" (crocodile), two creatures which, in a local myth, fought each other in order to gain the title of "the strongest and most powerful animal" in the area. It was said that the two powerful animals agreed for a truce and set boundaries; that the shark's domain would be in the sea while the crocodile's domain would be on the land. However one day the shark swam into the river estuary to hunt, this angered the crocodile, who declared it his territory. The Shark argued that the river was a water-realm which meant that it was shark territory, while the crocodile argued that the river flowed deep inland, so it was therefore crocodile territory. A ferocious fight resumed as the two animals bit each other. Finally the shark was badly bitten and fled to the open sea, and the crocodile finally ruled the estuarine area that today is the city. Another source alludes to a Jayabaya prophecy—a 12th-century psychic king of Kediri Kingdom—as he foresaw a fight between a giant white shark and a giant white crocodile taking place in the area, which is sometimes interpreted as a foretelling of the Mongol invasion of Java, a major conflict between the forces of the Kublai Khan, Mongol ruler of China, and those of Raden Wijaya's Majapahit in 1293. The two animals are now used as the city's symbol, with the two facing and circling each other, as depicted in a statue appropriately located near the entrance to the city zoo (see photo on the Surabaya page).[citation needed]
In language and as symbols
Main article: Crocodile tears
The term "crocodile tears" (and equivalents in other languages) refers to a false, insincere display of emotion, such as a hypocrite crying fake tears of grief. It is derived from an ancient anecdote that crocodiles weep in order to lure their prey, or that they cry for the victims they are eating, first told in the Bibliotheca by Photios I of Constantinople. The story is repeated in bestiaries such as De bestiis et aliis rebus. This tale was first spread widely in English in the stories of the Travels of Sir John Mandeville in the 14th century, and appears in several of Shakespeare's plays. In fact, crocodiles can and do generate tears, but they do not actually cry.
In the UK, a row of schoolchildren walking in pairs, or two by two is known as "crocodile".
Fashion logos
The French clothing company Lacoste features a crocodile in its logo. The American shoe company Crocs also uses this imagery in its logo.
The Asian elephant (Elephas maximus), also known as the Asiatic elephant, is the only living species of the genus Elephas and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, E. m. indicus from mainland Asia and E. m. sumatranus from the island of Sumatra. Formerly, there was also the Syrian elephant or Western Asiatic elephant (Elephas maximus asurus) which was the westernmost population of the Asian elephant (Elephas maximus). This subspecies became extinct in ancient times. Skeletal remains of E. m. asurus have been recorded from the Middle East: Iran, Iraq, Syria, and Turkey from periods dating between at least 1800 BC and likely 700 BC. It is one of only three living species of elephants or elephantids anywhere in the world, the others being the African bush elephant and African forest elephant. It is the second largest species of elephant after the African bush elephant.
The Asian elephant is the largest living land animal in Asia. Since 1986, the Asian elephant has been listed as Endangered on the IUCN Red List, as the population has declined by at least 50 per cent over the last three elephant generations, which is about 60–75 years. It is primarily threatened by loss of habitat, habitat degradation, fragmentation and poaching. In 2019, the wild population was estimated at 48,323–51,680 individuals. Female captive elephants have lived beyond 60 years when kept in semi-natural surroundings, such as forest camps. In zoos, Asian elephants die at a much younger age; captive populations are declining due to a low birth and high death rate.
The genus Elephas originated in Sub-Saharan Africa during the Pliocene and spread throughout Africa before expanding into the southern half of Asia. The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley civilisation dated to the 3rd millennium BC.
Evolution
The genus Elephas, of which the Asian elephant is the only living member, is the closest relative of the extinct mammoths. The two groups are estimated to have split from each other around 7 million years ago. The earliest Elephas species, Elephas ekorensis, is known from the Early Pliocene of East Africa, around 5-4.2 million years ago. The oldest remains of the genus in Asia are known from the Siwalik Hills in the Indian subcontinent, dating to the late Pliocene, around 3.6-3.2 million years ago, assigned to the species Elephas planifrons. The modern Asian elephant is suggested to have evolved from the species Elephas hysudricus, which first appeared at the beginning of the Early Pleistocene around 2.6 million years ago, and is primarily known from remains of Early-Middle Pleistocene age found on the Indian subcontinent.
In general, the Asian elephant is smaller than the African bush elephant and has the highest body point on the head. The back is convex or level. The ears are small with dorsal borders folded laterally. It has up to 20 pairs of ribs and 34 caudal vertebrae. The feet have five nail-like structures on each forefoot, and four on each hind foot. The forehead has two hemispherical bulges, unlike the flat front of the African elephants. Its long trunk or proboscis has only one fingerlike tip, in contrast to the African elephants which have two. Hence, the Asian species relies more on wrapping around a food item and squeezing it into its mouth, rather than grasping with the tip. Asian elephants have more muscle coordination and can perform more complex tasks.
Cows usually lack tusks; if tusks—in that case, called "tushes"—are present, they are barely visible and only seen when the mouth is open.[citation needed] The enamel plates of the molars are greater in number and closer together in Asian elephants. Some bulls may also lack tusks; these individuals are called "filsy makhnas", and are especially common among the Sri Lankan elephant population. A tusk from an 11 ft (3.4 m) tall elephant killed by Sir Victor Brooke measured 8 ft (2.4 m) in length, and nearly 17 in (43 cm) in circumference, and weighed 90 lb (41 kg). This tusk's weight is, however, exceeded by the weight of a shorter tusk of about 6 ft (1.8 m) in length which weighed 100 lb (45 kg), and there have reportedly been tusks weighing over 150 lb (68 kg).
Skin colour is usually grey, and may be masked by soil because of dusting and wallowing. Their wrinkled skin is movable and contains many nerve centres. It is smoother than that of African elephants and may be depigmented on the trunk, ears, or neck. The epidermis and dermis of the body average 18 mm (0.71 in) thick; skin on the dorsum is 30 mm (1.2 in) thick providing protection against bites, bumps, and adverse weather. Its folds increase surface area for heat dissipation. They can tolerate cold better than excessive heat. Skin temperature varies from 24 to 32.9 °C (75.2 to 91.2 °F). Body temperature averages 35.9 °C (96.6 °F).
Size
On average, when fully-grown, bulls are about 2.75 m (9.0 ft) tall at the shoulder and 4.0 t (4.4 short tons) in weight, while cows are smaller at about 2.40 m (7.9 ft) at the shoulder and 2.7 t (3.0 short tons) in weight. Sexual dimorphism in body size is relatively less pronounced in Asian elephants than in African bush elephants; with bulls averaging 15% and 23% taller in the former and latter respectively. Length of body and head including trunk is 5.5–6.5 m (18–21 ft) with the tail being 1.2–1.5 m (3.9–4.9 ft) long. The largest bull elephant ever recorded was shot by the Maharajah of Susang in the Garo Hills of Assam, India, in 1924, it weighed an estimated 7 t (7.7 short tons), stood 3.43 m (11.3 ft) tall at the shoulder and was 8.06 m (26.4 ft) long from head to tail. There are reports of larger individuals as tall as 3.7 m (12 ft).
Asian elephants inhabit grasslands, tropical evergreen forests, semi-evergreen forests, moist deciduous forests, dry deciduous forests and dry thorn forests, in addition to cultivated and secondary forests and scrublands. Over this range of habitat types elephants occur from sea level to over 3,000 m (9,800 ft). In the eastern Himalaya in northeast India, they regularly move up above 3,000 m (9,800 ft) in summer at a few sites.
In China, the Asian elephant survives only in the prefectures of Xishuangbanna, Simao, and Lincang of southern Yunnan. The estimated population is around 300 individual (in 2020).
In Bangladesh, some isolated populations survive in the south-east Chittagong Hills.[10] A herd of 20–25 wild elephants was reported as being present in the Garo Hills of Mymensingh in the late-1990s, being detached from a big herd in the Peack hills of India and prevented from returning by fences put up in the meantime by the Indian border security force. The herd was estimated at about 60 individuals in 2014.
In Malaysia's northern Johor and Terengganu National Park, two Asian elephants were tracked using satellite tracking technology. They spent most of their time in secondary or "logged-over forest" and travelled 75% of their time in an area less than 1.5 km (0.93 mi) away from a water source.
Asian elephants are crepuscular. They are classified as megaherbivores and consume up to 150 kg (330 lb) of plant matter per day. They are generalist feeders, and are both grazers and browsers. They are known to feed on at least 112 different plant species, most commonly of the order Malvales, as well as the legume, palm, sedge and true grass families. They browse more in the dry season with bark constituting a major part of their diet in the cool part of that season. They drink at least once a day and are never far from a permanent source of fresh water.They need 80–200 litres of water a day and use even more for bathing. At times, they scrape the soil for clay or minerals.
Cows and calves move about together as groups, while bulls disperse from their mothers upon reaching adolescence. Bulls are solitary or form temporary "bachelor groups". Cow-calf units generally tend to be small, typically consisting of three adults (most likely related females) and their offspring. Larger groups of as many as 15 adult females have also been recorded. Seasonal aggregations of 17 individuals including calves and young adults have been observed in Sri Lanka's Uda Walawe National Park. Until recently, Asian elephants, like African elephants, were thought to be under the leadership of older adult females, or matriarchs. It is now recognized that cows form extensive and very fluid social networks, with varying degrees of associations between individuals. Social ties generally tend to be weaker than in African elephants.
Unlike African elephants, which rarely use their forefeet for anything other than digging or scraping soil, Asian elephants are more agile at using their feet in conjunction with the trunk for manipulating objects. They can sometimes be known for their violent behavior.
Asian elephants are recorded to make three basic sounds: growls, squeaks and snorts. Growls in their basic form are used for short distance communication. During mild arousal, growls resonate in the trunk and become rumbles while for long-distance communication, they escalate into roars. Low-frequency growls are infrasonic and made in many contexts. Squeaks come in two forms: chirpings and trumpets. Chirping consists of multiple short squeaks and signals conflict and nervousness. Trumpets are lengthened squeaks with increased loudness and are produced during extreme arousal. Snorts signal changes in activity and increase in loudness during mild or strong arousal. During the latter case, when an elephant bounces the tip of the trunk, it creates booms which serve as threat displays: 142 Elephants can distinguish low-amplitude sounds.
Rarely, tigers have been recorded attacking and killing calves, especially if the calves become separated from their mothers, stranded from their herd, or orphaned. Adults are largely invulnerable to natural predation. There is a singular anecdotal case of a mother Asian elephant allegedly being killed alongside her calf; however, this account is contestable. In 2011 and 2014, two instances were recorded of tigers successfully killing adult elephants; one by a single tiger in Jim Corbett National Park on a 20-year-old young adult elephant cow, and another on a 28-year-old sick adult bull in Kaziranga National Park further east, which was taken down and eaten by several tigers hunting cooperatively. Elephants appear to distinguish between the growls of larger predators like tigers and smaller predators like leopards; they react to leopards less fearfully and more aggressively.
Reproduction in Asian elephants can be attributed to the production and perception of signaling compounds called pheromones. These signals are transmitted through various bodily fluids. They are commonly released in urine but in males they are also found in special secretions from the temporal glands. Once integrated and perceived, these signals provide the receiver with information about the reproductive status of the sender. If both parties are ready to breed, reproductive ritualic behavior occurs and the process of sexual reproduction proceeds.
Bulls will fight one another to get access to oestrus cows. Strong fights over access to females are extremely rare. Bulls reach sexual maturity around the age of 12–15. Between the ages of 10 and 20 years, bulls undergo an annual phenomenon known as "musth". This is a period where the testosterone level is up to 100 times greater than non-musth periods, and they become aggressive. Secretions containing pheromones occur during this period, from the paired temporal glands located on the head between the lateral edge of the eye and the base of the ear. The aggressive behaviors observed during musth can be attributed to varying amounts of frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane) throughout the maturation process of bulls. Frontalin is a pheromone that was first isolated in bark beetles but can also be produced in the bulls of both Asian and African Elephants. The compound can be excreted through urine as well as through the temporal glands of the bull, allowing signaling to occur. During musth, increased concentrations of frontalin in the bull's urine communicate the reproductive status of the bull to female elephants.
Similar to other mammals, hormone secretion in female elephants is regulated by an estrous cycle. This cycle is regulated by surges in Luteinizing Hormone that are observed 3 weeks from each other. This type of estrous cycle has also been observed in African Elephants but is not known to affect other mammals. The first surge in Luteinizing Hormone is not followed by the release of an egg from the ovaries. However, some female elephants still exhibit the expected mating protocols during this surge. Female elephants give ovulatory cues by utilizing sex pheromones. A principal component thereof, (Z)-7-dodecen-1-yl acetate, has also been found to be a sex pheromone in numerous species of insects. In both insects and elephants, this chemical compound is used as an attractant to assist the mating process. In elephants, the chemical is secreted through urination and this aids in the attraction of bulls to mate. Once detected, the chemical stimulates the vomeronasal organ of the bull, thus providing information on the maturity of the female.
Reproductive signaling exchange between male and female elephants are transmitted through olfactory cues in bodily fluids. In males, the increase in frontalin during musth heightens their sensitivity to the (Z)-7-dodecen-1-yl acetate produced by female elephants. Once perceived by receptors in the trunk, a sequence of ritualistic behaviors follow. The responses in males vary based on both the stage of development and the temperament of the elephant. This process of receiving and processing signals through the trunk is referred to as flehmen. The difference in body movements give cues to gauge if the male is interested in breeding with the female that produced the secretion. A bull that is ready to breed will move closer to the urine and in some cases an erection response is elicited. A bull that is not ready to breed will be timid and try to dissociate themselves from the signal.
In addition to reproductive communication, chemosensory signaling is used to facilitate same-sex interactions. When less developed males detect pheromones from a male in musth, they often retreat to avoid coming in contact with aggressive behaviors. Female elephants have also been seen to communicate with each other through pheromone in urine. The purpose of this type of intersex communication is still being investigated. However, there are clear differences in signaling strength and receiver response throughout different stages of the estrous cycle.
The gestation period is 18–22 months, and the cow gives birth to one calf, only occasionally twins. The calf is fully developed by the 19th month, but stays in the womb to grow so that it can reach its mother to feed. At birth, the calf weighs about 100 kg (220 lb), and is suckled for up to three years. Once a female gives birth, she usually does not breed again until the first calf is weaned, resulting in a four to five-year birth interval. During this period, mother to calf communication primarily takes place through temporal means. However, male calves have been known to develop sex pheromone-producing organs at a young age. Early maturity of the vomeronasal organ allows immature elephants to produce and receive pheromones. It is unlikely that the integration of these pheromones will result in a flehmen response in a calf. Females stay on with the herd, but mature males are chased away.
Female Asian elephants sexually mature around the age of 10~15 and keep growing until 30, while males fully mature at more than the age of 25, and constantly grow throughout their life. Average elephant life expectancy is 60 years in the wild and 80 in captivity, although this has been exaggerated in the past. Generation length of the Asian elephant is 22 years.
Asian elephants have a very large and highly developed neocortex, a trait also shared by humans, apes and certain dolphin species. They have a greater volume of cerebral cortex available for cognitive processing than all other existing land animals.[citation needed] Results of studies indicate that Asian elephants have cognitive abilities for tool use and tool-making similar to great apes. They exhibit a wide variety of behaviours, including those associated with grief, learning, allomothering, mimicry, play, altruism, use of tools, compassion, cooperation, self-awareness, memory, and language. Elephants reportedly head to safer ground during natural disasters like tsunamis and earthquakes, but data from two satellite-collared Sri Lankan elephants indicate this may be untrue.
Several students of elephant cognition and neuroanatomy are convinced that Asian elephants are highly intelligent and self-aware. Others contest this view.
Threats
The pre-eminent threats to the Asian elephant today are the loss, degradation and fragmentation of its habitat, which leads to increasing conflicts between humans and elephants. Asian elephants are poached for ivory and a variety of other products including meat and leather. The demand for elephant skin has risen due to it being an increasingly-common ingredient in traditional Chinese medicine.
Human–elephant conflict
In some parts of Asia, people and elephants have co-existed for thousands of years. In other areas, people and elephants come into conflict, resulting in violence, and ultimately, the displacement of elephants.
Destruction of forests through logging, encroachment, slash-and-burn, shifting cultivation, and monoculture tree plantations are major threats to the survival of elephants. Human–elephant conflicts occur when elephants raid crops of shifting cultivators in fields, which are scattered over a large area interspersed with forests. Depredation in human settlements is another major area of human–elephant conflict occurring in small forest pockets, encroachments into elephant habitat, and on elephant migration routes. However, studies in Sri Lanka indicate that traditional slash-and-burn agriculture may create optimal habitat for elephants by creating a mosaic of successional-stage vegetation. Populations inhabiting small habitat fragments are much more liable to come into conflict with humans.
Human-elephant conflict can be categorised into:
ultimate causes including growing human population, large-scale development projects and poor top-down governance;
proximate causes including habitat loss due to deforestation, disruption of elephant migratory routes, expansion of agriculture and illegal encroachment into protected areas.
Development such as border fencing along the India–Bangladesh border has become a major impediment to the free movement of elephants. In Assam, more than 1,150 humans and 370 elephants died as a result of human-elephant conflict between 1980 and 2003. In India alone, over 400 people are killed by elephants every year, and 0.8 to 1 million hectares are damaged, affecting at least 500,000 families across the country. Moreover, elephants are known to destroy crops worth up to US$2–3 million annually. This has major impacts on the welfare and livelihoods of local communities, as well as the future conservation of this species. In countries like Bangladesh and Sri Lanka, the Asian elephant is one of the most feared wild animals, even though they are less deadly than other local animals such as venomous snakes (which were estimated to claim more than 30 times more lives in Sri Lanka than elephants). As a whole, Asian elephants display highly sophisticated and sometimes unpredictable behaviour. Most untamed elephants try to avoid humans, but if they are caught off guard by any perceived physical threat, including humans, they will likely charge. This is especially true of males in musth and of females with young. Gunfire and other similar methods of deterring, which are known to be effective against many kinds of wild animals including tigers, may or may not work with elephants, and can even worsen the situation. Elephants that have been abused by humans in the past often become "rogue elephants", which regularly attack people with no provocation.
Poaching
For ivory
The demand for ivory during the 1970s and 1980s, particularly in East Asia, led to rampant poaching and the serious decline of elephants in both Africa and Asia. In Thailand, the illegal trade in live elephants and ivory still flourishes. Although the amount of ivory being openly sold has decreased substantially since 2001, Thailand still has one of the largest and most active black markets for ivory seen anywhere in the world. Tusks from Thai-poached elephants also enter the market; between 1992 and 1997 at least 24 male elephants were killed for their tusks.
Up to the early 1990s, Vietnamese ivory craftsmen used exclusively Asian elephant ivory from Vietnam and neighbouring Lao and Cambodia. Before 1990, there were few tourists and the low demand for worked ivory could be supplied by domestic elephants. Economic liberalisation and an increase in tourism raised both local and visitors' demands for worked ivory, which resulted in heavy poaching.
For skin
The skin of the Asian elephant is used as an ingredient in Chinese medicine as well as in the manufacture of ornamental beads. The practice has been aided by China's State Forestry Administration (SFA), which has issued licences for the manufacture and sale of pharmaceutical products containing elephant skin, thereby making trading legal. In 2010, four skinned elephants were found in a forest in Myanmar; 26 elephants were killed by poachers in 2013 and 61 in 2016. According to the NGO Elephant Family, Myanmar is the main source of elephant skin, where a poaching crisis has developed rapidly since 2010.
Handling methods
Young elephants are captured and illegally imported to Thailand from Myanmar for use in the tourism industry; calves are used mainly in amusement parks and are trained to perform various stunts for tourists.
The calves are often subjected to a 'breaking in' process, which may involve being tied up, confined, starved, beaten and tortured; as a result, two-thirds may perish. Handlers use a technique known as the training crush, in which "handlers use sleep-deprivation, hunger, and thirst to "break" the elephants' spirit and make them submissive to their owners"; moreover, handlers drive nails into the elephants' ears and feet.
Disease
The Asian elephant is listed on CITES Appendix I. It is a quintessential flagship species, deployed to catalyze a range of conservation goals, including habitat conservation at landscape scales, generating public awareness on conservation issues, and mobilisation as a popular cultural icon both in India and the West. A key aspect of Asian elephant conservation is connectivity, and preserving the preferred movement routes of elephants through areas of high vegetation cover and with "low human population density".
The World Elephant Day has been celebrated on 12 August since 2012. Events are organized to divulge information and to engage people about the problems that the Asian elephant is facing. August has been established as the Asian Elephant Awareness Month by zoos and conservation partners in the United States.
In China, Asian elephants are under first-level protection. Yunnan province has 11 national and regional nature reserves. In total, the covered protected area in China is about 510,000 km2 (200,000 sq mi). In 2020, the population of Asian elephants in Yunnan was estimated at around 300 individuals. As conflicts between humans and wild elephants have emerged around protected areas in the last years, the prefecture of Xishuangbanna built food bases and planted bananas and bamboo to create a better habitat.
In Thailand, Salakpra Wildlife Sanctuary and Tham Than Lot National Park are protected areas hosting around 250–300 elephants, according to figures from 2013. In recent years the National Park has faced issues due to encroachment and over-exploitation.
In India, the National Board of Wildlife did a recommendation, allowing coal mining in the Dehing Patkai elephant reserve in April 2020. The decision raised concerns between students and environmental activists who launched an online campaign to stop the project.
In captivity
About half of the global zoo elephant population is kept in European zoos, where they have about half the median life span of conspecifics in protected populations in range countries. This discrepancy is clearest in Asian elephants: infant mortality is twice that seen in Burmese timber camps, and adult survivorship in zoos has not improved significantly in recent years. One risk factor for Asian zoo elephants is being moved between institutions, with early removal from the mother tending to have additional adverse effects. Another risk factor is being born into a zoo rather than being imported from the wild, with poor adult survivorship in zoo-born Asians apparently being conferred prenatally or in early infancy. Likely causes for compromised survivorship is stress and/or obesity. Foot problems are commonly observed in captive elephants. These are related to lack of exercise, long hours standing on hard substrates, and contamination resulting from standing in their dung. Many of these problems are treatable. However, mistreatment may lead to serious disability or death.
Demographic analysis of captive Asian elephants in North America indicates that the population is not self-sustaining. First year mortality is nearly 30 per cent, and fecundity is extremely low throughout the prime reproductive years. Data from North American and European regional studbooks from 1962 to 2006 were analysed for deviations in the birth and juvenile death sex ratios. Of 349 captive calves born, 142 died prematurely. They died within one month of birth, major causes being stillbirth and infanticide by either the calf's mother or by one of the exhibition mates. The sex ratio of stillbirths in Europe was found to have a tendency for excess of males.
In culture
Bones of Asian elephants excavated at Mohenjo-daro in the Indus Valley indicate that they were tamed in the Indus Valley civilization and used for work. Decorated elephants are also depicted on seals and were modelled in clay.
The Asian elephant became a siege engine, a mount in war, a status symbol, a beast of burden, and an elevated platform for hunting during historical times in South Asia.
Asian elephants have been captured from the wild and tamed for use by humans. Their ability to work under instruction makes them particularly useful for carrying heavy objects. They have been used particularly for timber-carrying in jungle areas. Other than their work use, they have been used in war, in ceremonies, and for carriage. It is reported that war elephants are still in use by the Kachin Independence Army (KIA) to take control of Kachin State in northern Myanmar from Myanmar's military. The KIA use about four dozen elephants to carry supplies.
The Asian elephant plays an important part in the culture of the subcontinent and beyond, being featured prominently in the Panchatantra fables and the Buddhist Jataka tales. They play a major role in Hinduism: the god Ganesha's head is that of an elephant, and the "blessings" of a temple elephant are highly valued. Elephants are frequently used in processions where the animals are adorned with festive outfits.
The Asian elephant is depicted in several Indian manuscripts and treatises. Notable amongst these is the Matanga Lila (elephant sport) of Nilakantha. The manuscript Hastividyarnava is from Assam in northeast India.
In the Burmese, Thai and Sinhalese animal and planetary zodiac, the Asian elephant, both tusked and tuskless, are the fourth and fifth animal zodiacs of the Burmese, the fourth animal zodiac of the Thai, and the second animal zodiac of the Sinhalese people of Sri Lanka. Similarly, the elephant is the twelfth animal zodiac in the Dai animal zodiac of the Dai people in southern China.
Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans (family Alligatoridae), the gharial and false gharial (family Gavialidae) among other extinct taxa.
Although they appear similar, crocodiles, alligators and the gharial belong to separate biological families. The gharial, with its narrow snout, is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head, with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is that the upper and lower jaws of the crocodiles are the same width, and the teeth in the lower jaw fall along the edge or outside the upper jaw when the mouth is closed; therefore, all teeth are visible, unlike an alligator, which possesses in the upper jaw small depressions into which the lower teeth fit. Also, when the crocodile's mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the protruding tooth is the most reliable feature to define the species' family. Crocodiles have more webbing on the toes of the hind feet and can better tolerate saltwater due to specialized salt glands for filtering out salt, which are present, but non-functioning, in alligators. Another trait that separates crocodiles from other crocodilians is their much higher levels of aggression.
Crocodile size, morphology, behaviour and ecology differ somewhat among species. However, they have many similarities in these areas as well. All crocodiles are semiaquatic and tend to congregate in freshwater habitats such as rivers, lakes, wetlands and sometimes in brackish water and saltwater. They are carnivorous animals, feeding mostly on vertebrates such as fish, reptiles, birds and mammals, and sometimes on invertebrates such as molluscs and crustaceans, depending on species and age. All crocodiles are tropical species that, unlike alligators, are very sensitive to cold. They separated from other crocodilians during the Eocene epoch, about 55 million years ago. Many species are at the risk of extinction, some being classified as critically endangered.
Etymology
The word crocodile comes from the Ancient Greek krokódilos (κροκόδιλος) meaning 'lizard', used in the phrase ho krokódilos tou potamoú, "the lizard of the (Nile) river". There are several variant Greek forms of the word attested, including the later form krokódeilos (κροκόδειλος) found cited in many English reference works. In the Koine Greek of Roman times, krokodilos and krokodeilos would have been pronounced identically, and either or both may be the source of the Latinized form crocodīlus used by the ancient Romans. It has been suggested, but it is not certain that the word crocodilos or crocodeilos is a compound of krokè ('pebbles'), and drilos/dreilos ('worm'), although drilos is only attested as a colloquial term for 'penis'. It is ascribed to Herodotus, and supposedly describes the basking habits of the Egyptian crocodile.
The form crocodrillus is attested in Medieval Latin. It is not clear whether this is a medieval corruption or derives from alternative Greco-Latin forms (late Greek corcodrillos and corcodrillion are attested). A (further) corrupted form cocodrille is found in Old French and was borrowed into Middle English as cocodril(le). The Modern English form crocodile was adapted directly from the Classical Latin crocodīlus in the 16th century, replacing the earlier form. The use of -y- in the scientific name Crocodylus (and forms derived from it) is a corruption introduced by Laurenti (1768).
Species
Species nameImageDistributionDescription/Comments
American crocodile (Crocodylus acutus)Throughout the Caribbean Basin, including many of the Caribbean islands and South Florida.A larger sized species, with a greyish colour and a prominent V-shaped snout. Prefers brackish water, but also inhabits lower stretches of rivers and true marine environments. This is one of the rare species that exhibits regular sea-going behaviour, which explains the great distribution throughout the Caribbean. It is also found in hypersaline lakes such as Lago Enriquillo, in the Dominican Republic, which has one of the largest populations of this species. Diet consists mostly of aquatic and terrestrial vertebrates. Classified as Vulnerable, but certain local populations under greater threat.
Hall's New Guinea crocodile (Crocodylus halli)The island of New Guinea, south of the New Guinea HighlandsA smaller species that closely resembles and was long classified under the New Guinea crocodile, which it is now considered to be genetically distinct from. It lives south of the mountain barrier that divides the two species' ranges. It can be physically distinguished from the New Guinea crocodile by its shorter maxilla and enlarged postcranial elements. Cranial elements can still widely vary within the species, with populations from Lake Murray having much wider heads than those from the Aramia River.
Orinoco crocodile (Crocodylus intermedius)Colombia and VenezuelaThis is a large species with a relatively elongated snout and a pale tan coloration with scattered dark brown markings. Lives primarily in the Orinoco Basin. Despite having a rather narrow snout, preys on a wide variety of vertebrates, including large mammals. It is a Critically Endangered species.
Freshwater crocodile (Crocodylus johnstoni)Northern AustraliaA smaller species with a narrow and elongated snout. It has light brown coloration with darker bands on body and tail. Lives in rivers with considerable distance from the sea, to avoid confrontations with saltwater crocodiles. Feeds mostly on fish and other small vertebrates.
Philippine crocodile (Crocodylus mindorensis)Endemic to the PhilippinesThis is a relatively small species with a rather broader snout. It has heavy dorsal armour and a golden-brown colour that darkens as the animal matures. Prefers freshwater habitats and feeds on a variety of small to medium sized vertebrates. This species is Critically Endangered and the most severely threatened species of crocodile.
Morelet's crocodile (Crocodylus moreletii)Atlantic regions of Mexico, Belize and GuatemalaA small to medium sized crocodile with a rather broad snout. It has a dark greyish-brown colour and is found in mostly various freshwater habitats. Feeds on mammals, birds and reptiles. It is listed as Least Concern.
Nile crocodile (Crocodylus niloticus)Sub-saharan AfricaA large and aggressive species with a broad snout, especially in older animals. It has a dark bronze coloration and darkens as the animal matures. Lives in a variety of freshwater habitats but is also found in brackish water. It is an apex predator that is capable of taking a wide array of African vertebrates, including large ungulates and other predators. This species is listed as Least Concern.
New Guinea crocodile (Crocodylus novaeguineae)The island of New Guinea, north of the New Guinea HighlandsA smaller species of crocodile with a grey-brown colour and dark brown to black markings on the tail. The young have a narrower V-shaped snout that becomes wider as the animal matures. Prefers freshwater habitats, even though is tolerant to salt water, in order to avoid competition and predation by the saltwater crocodile. This species feeds on small to mid-sized vertebrates.
Mugger crocodile (Crocodylus palustris)The Indian subcontinent and surrounding countriesThis is a modest sized crocodile with a very broad snout and an alligator-like appearance. It has dark-grey to brown coloration. Enlarged scutes around the neck make it a heavily armoured species. Prefers slow moving rivers, swamps and lakes. It can also be found in coastal swamps but avoids areas populated by saltwater crocodiles. Feeds on a wide array of vertebrates.
Saltwater crocodile (Crocodylus porosus)Throughout Southeast Asia, Northern Australia and surrounding watersThe largest living reptile and most aggressive of all crocodiles. It is a big-headed species and has a relatively broad snout, especially when older. The coloration is pale yellow with black stripes when young but dark greenish-drab coloured as adults. Lives in brackish and marine environments as well as lower stretches of rivers. This species has the greatest distribution of all crocodiles. Tagged specimens showed long-distance marine travelling behaviour. It is the apex predator throughout its range and preys on virtually any animal within its reach. It is classified as Least Concern with several populations under greater risk.
Borneo crocodile (Crocodylus raninus)Island of Borneo in Southeast AsiaA freshwater species of crocodile that has been considered a synonym of the saltwater crocodile.
Cuban crocodile (Crocodylus rhombifer)Found only in the Zapata Swamp and Isle of Youth of CubaIt is a small but extremely aggressive species of crocodile that prefers freshwater swamps. The coloration is vibrant even as adults and the scales have a "pebbled" appearance. It is a relatively terrestrial species with agile locomotion on land, and sometimes displays terrestrial hunting. The snout is broad with a thick upper-jaw and large teeth. The unique characteristics and fossil record indicates a rather specialized diet in the past, preying on megafauna such as the giant sloth. This species sometimes displays pack-hunting behaviour, which might have been the key to hunting large species in the past, despite its small size.[ Today most prey are small to medium sized vertebrates. It is Critically Endangered, and the remaining wild population is under threat of hybridization.
Siamese crocodile (Crocodylus siamensis)Indonesia, Brunei, East Malaysia and southern IndochinaA fairly small crocodile that prefers freshwater habitats. It has a relatively broad snout and olive-green to dark green coloration. It feeds on a variety of small to mid-sized vertebrates. Listed as Critically Endangered, but might be already extinct in the wild; status is unknown.
West African crocodile (Crocodylus suchus)Western and Central AfricaRecent studies revealed that this is distinct species from the larger Nile crocodile. It has a slightly narrower snout and is much smaller compared to its larger cousin.
Osborn’s dwarf crocodile (Osteolaemus osborni)Western AfricaIt is the smallest of all living crocodiles. It is a heavily armoured species with uniform black coloration in adults, while juveniles have a lighter brown banding. Lives in the tropical forests of Western Africa. Feeds on small vertebrates and large aquatic invertebrates. It is a fairly terrestrial species and exhibits terrestrial hunting, especially at night.
Dwarf crocodile (Osteolaemus tetraspis)Western AfricaIt is the smallest of all living crocodiles. It belongs to its own monotypic genus; however, new studies indicate there might be two or even three distinct species. It is a heavily armoured species with uniform black coloration in adults, while juveniles have a lighter brown banding. Lives in the tropical forests of Western Africa. Feeds on small vertebrates and large aquatic invertebrates. It is a fairly terrestrial species and exhibits terrestrial hunting, especially at night. This species is classified as Vulnerable.
West African slender-snouted crocodile (Mecistops cataphractus)Western AfricaA medium sized species with a narrow and elongated snout. Lives in freshwater habitats within tropical forests of the continent. Feeds mostly on fish but also other small to medium sized vertebrates. It is a Critically Endangered species.
Central African slender-snouted crocodile (Mecistops leptorhynchus)Central AfricaA medium sized species found in watery areas in dense rainforest. Feeds largely on fish. Insufficient conservation data, but was classified as Critically Endangered when lumped with M. cataphractus, although M. leptorhynchus is doing better in its home range.
For information on Tomistoma or false gharial, that is recently not considered as a true crocodile, see False gharial.
Characteristics
A crocodile's physical traits allow it to be a successful predator. Its external morphology is a sign of its aquatic and predatory lifestyle. Its streamlined body enables it to swim swiftly; it also tucks its feet to the side while swimming, making it faster by decreasing water resistance. Crocodiles have webbed feet which, though not used to propel them through the water, allow them to make fast turns and sudden moves in the water or initiate swimming. Webbed feet are an advantage in shallow water, where the animals sometimes move around by walking. Crocodiles have a palatal flap, a rigid tissue at the back of the mouth that blocks the entry of water. The palate has a special path from the nostril to the glottis that bypasses the mouth. The nostrils are closed during submergence.
Like other archosaurs, crocodilians are diapsid, although their post-temporal fenestrae are reduced. The walls of the braincase are bony but lack supratemporal and postfrontal bones. Their tongues are not free, but held in place by a membrane that limits movement; as a result, crocodiles are unable to stick out their tongues. Crocodiles have smooth skin on their bellies and sides, while their dorsal surfaces are armoured with large osteoderms. The armoured skin has scales and is thick and rugged, providing some protection. They are still able to absorb heat through this armour, as a network of small capillaries allows blood through the scales to absorb heat. The osteoderms are highly vascularised and aid in calcium balance, both to neutralize acids while the animal cannot breathe underwater and to provide calcium for eggshell formation. Crocodilian tegument have pores believed to be sensory in function, analogous to the lateral line in fishes. They are particularly seen on their upper and lower jaws. Another possibility is that they are secretory, as they produce an oily substance which appears to flush mud off.
Size
Size greatly varies among species, from the dwarf crocodile to the saltwater crocodile. Species of the dwarf crocodile Osteolaemus grow to an adult size of just 1.5 to 1.9 m (4.9 to 6.2 ft), whereas the saltwater crocodile can grow to sizes over 6 m (20 ft) and weigh over 1,000 kg (2,200 lb). Several other large species can reach over 5.2 m (17 ft) long and weigh over 900 kg (2,000 lb). Crocodilians show pronounced sexual dimorphism, with males growing much larger and more rapidly than females. Despite their large adult sizes, crocodiles start their lives at around 20 cm (7.9 in) long. The largest species of crocodile is the saltwater crocodile, found in eastern India, northern Australia, throughout South-east Asia, and in the surrounding waters.
The brain volume of two adult crocodiles was 5.6 cm3 for a spectacled caiman and 8.5 cm3 for a larger Nile crocodile.
The largest crocodile ever held in captivity is a saltwater–Siamese hybrid named Yai (Thai: ใหญ่, meaning big; born 10 June 1972) at the Samutprakarn Crocodile Farm and Zoo, Thailand. This animal measures 6 m (20 ft) in length and weighs 1,200 kg (2,600 lb).
The longest crocodile captured alive was Lolong, a saltwater crocodile which was measured at 6.17 m (20.2 ft) and weighed at 1,075 kg (2,370 lb) by a National Geographic team in Agusan del Sur Province, Philippines.
Teeth
Crocodiles are polyphyodonts; they are able to replace each of their 80 teeth up to 50 times in their 35- to 75-year lifespan. Next to each full-grown tooth, there is a small replacement tooth and an odontogenic stem cell in the dental lamina in standby that can be activated if required.
Biology and behaviour
Crocodilians are more closely related to birds and dinosaurs than to most animals classified as reptiles, the three families being included in the group Archosauria ('ruling reptiles'). Despite their prehistoric look, crocodiles are among the more biologically complex reptiles. Unlike other reptiles, a crocodile has a cerebral cortex and a four-chambered heart. Crocodilians also have the functional equivalent of a diaphragm by incorporating muscles used for aquatic locomotion into respiration. Salt glands are present in the tongues of crocodiles and they have a pore opening on the surface of the tongue, a trait that separates them from alligators. Salt glands are dysfunctional in Alligatoridae. Their function appears to be similar to that of salt glands in marine turtles. Crocodiles do not have sweat glands and release heat through their mouths. They often sleep with their mouths open and may pant like a dog. Four species of freshwater crocodile climb trees to bask in areas lacking a shoreline.
Senses
Crocodiles have acute senses, an evolutionary advantage that makes them successful predators. The eyes, ears and nostrils are located on top of the head, allowing the crocodile to lie low in the water, almost totally submerged and hidden from prey.
Vision
Crocodiles have very good night vision, and are mostly nocturnal hunters. They use the disadvantage of most prey animals' poor nocturnal vision to their advantage. The light receptors in crocodilians' eyes include cones and numerous rods, so it is assumed all crocodilians can see colours. Crocodiles have vertical-slit shaped pupils, similar to those of domestic cats. One explanation for the evolution of slit pupils is that they exclude light more effectively than a circular pupil, helping to protect the eyes during daylight. On the rear wall of the eye is a tapetum lucidum, which reflects incoming light back onto the retina, thus utilizing the small amount of light available at night to best advantage. In addition to the protection of the upper and lower eyelids, crocodiles have a nictitating membrane (sometimes called a "third eye-lid") that can be drawn over the eye from the inner corner while the lids are open. The eyeball surface is thus protected under the water while a certain degree of vision is still possible.
Olfaction
Crocodilian sense of smell is also very well developed, aiding them to detect prey or animal carcasses that are either on land or in water, from far away. It is possible that crocodiles use olfaction in the egg prior to hatching.
Chemoreception in crocodiles is especially interesting because they hunt in both terrestrial and aquatic surroundings. Crocodiles have only one olfactory chamber and the vomeronasal organ is absent in the adults indicating all olfactory perception is limited to the olfactory system. Behavioural and olfactometer experiments indicate that crocodiles detect both air-borne and water-soluble chemicals and use their olfactory system for hunting. When above water, crocodiles enhance their ability to detect volatile odorants by gular pumping, a rhythmic movement of the floor of the pharynx. Crocodiles close their nostrils when submerged, so olfaction underwater is unlikely. Underwater food detection is presumably gustatory and tactile.
Hearing
Crocodiles can hear well; their tympanic membranes are concealed by flat flaps that may be raised or lowered by muscles.
Touch
The touch sensors, concentrated in crocodile skin, can be thicker than those in human fingerprints. Crocodiles can feel the touch on their skin.
Cranial: The upper and lower jaws are covered with sensory pits, visible as small, black speckles on the skin, the crocodilian version of the lateral line organs seen in fish and many amphibians, though arising from a completely different origin. These pigmented nodules encase bundles of nerve fibers innervated beneath by branches of the trigeminal nerve. They respond to the slightest disturbance in surface water, detecting vibrations and small pressure changes as small as a single drop. This makes it possible for crocodiles to detect prey, danger and intruders, even in total darkness. These sense organs are known as domed pressure receptors (DPRs).
Post-Cranial: While alligators and caimans have DPRs only on their jaws, crocodiles have similar organs on almost every scale on their bodies. The function of the DPRs on the jaws is clear; to catch prey, but it is still not clear what the function is of the organs on the rest of the body. The receptors flatten when exposed to increased osmotic pressure, such as that experienced when swimming in sea water hyperosmotic to the body fluids. When contact between the integument and the surrounding sea water solution is blocked, crocodiles are found to lose their ability to discriminate salinities. It has been proposed that the flattening of the sensory organ in hyperosmotic sea water is sensed by the animal as "touch", but interpreted as chemical information about its surroundings. This might be why in alligators they are absent on the rest of the body.
Hunting and diet
Crocodiles are ambush predators, waiting for fish or land animals to come close, then rushing out to attack. Crocodiles mostly eat fish, amphibians, crustaceans, molluscs, birds, reptiles, and mammals, and they occasionally cannibalize smaller crocodiles. What a crocodile eats varies greatly with species, size and age. From the mostly fish-eating species, like the slender-snouted and freshwater crocodiles, to the larger species like the Nile crocodile and the saltwater crocodile that prey on large mammals, such as buffalo, deer and wild boar, diet shows great diversity. Diet is also greatly affected by the size and age of the individual within the same species. All young crocodiles hunt mostly invertebrates and small fish, gradually moving on to larger prey. Being ectothermic (cold-blooded) predators, they have a very slow metabolism, so they can survive long periods without food. Despite their appearance of being slow, crocodiles have a very fast strike and are top predators in their environment, and various species have been observed attacking and killing other predators such as sharks and big cats. Crocodiles are also known to be aggressive scavengers who feed upon carrion and steal from other predators. Evidence suggests that crocodiles also feed upon fruits, based on the discovery of seeds in stools and stomachs from many subjects as well as accounts of them feeding.
Crocodiles have the most acidic stomach of any vertebrate. They can easily digest bones, hooves and horns. The BBC TV reported that a Nile crocodile that has lurked a long time underwater to catch prey builds up a large oxygen debt. When it has caught and eaten that prey, it closes its right aortic arch and uses its left aortic arch to flush blood loaded with carbon dioxide from its muscles directly to its stomach; the resulting excess acidity in its blood supply makes it much easier for the stomach lining to secrete more stomach acid to quickly dissolve bulks of swallowed prey flesh and bone. Many large crocodilians swallow stones (called gastroliths or stomach stones), which may act as ballast to balance their bodies or assist in crushing food, similar to grit ingested by birds. Herodotus claimed that Nile crocodiles had a symbiotic relationship with certain birds, such as the Egyptian plover, which enter the crocodile's mouth and pick leeches feeding on the crocodile's blood; with no evidence of this interaction actually occurring in any crocodile species, it is most likely mythical or allegorical fiction.
Bite
Since they feed by grabbing and holding onto their prey, they have evolved sharp teeth for piercing and holding onto flesh, and powerful muscles to close the jaws and hold them shut. The teeth are not well-suited to tearing flesh off of large prey items as are the dentition and claws of many mammalian carnivores, the hooked bills and talons of raptorial birds, or the serrated teeth of sharks. However, this is an advantage rather than a disadvantage to the crocodile since the properties of the teeth allow it to hold onto prey with the least possibility of the prey animal escaping. Cutting teeth, combined with the exceptionally high bite force, would pass through flesh easily enough to leave an escape opportunity for prey. The jaws can bite down with immense force, by far the strongest bite of any animal. The force of a large crocodile's bite is more than 5,000 lbf (22,000 N), which was measured in a 5.5 m (18 ft) Nile crocodile, in the field; comparing to 335 lbf (1,490 N) for a Rottweiler, 800 lbf (3,600 N) for a hyena, 2,200 lbf (9,800 N) for an American alligator, and 4,095 lbf (18,220 N) for the largest confirmed great white shark.
A 5.2 m (17 ft) long saltwater crocodile has been confirmed as having the strongest bite force ever recorded for an animal in a laboratory setting. It was able to apply a bite force value of 3,700 lbf (16,000 N), and thus surpassed the previous record of 2,125 lbf (9,450 N) made by a 3.9 m (13 ft) long American alligator. Taking the measurements of several 5.2 m (17 ft) crocodiles as reference, the bite forces of 6-m individuals were estimated at 7,700 lbf (34,000 N). The study, led by Dr. Gregory M. Erickson, also shed light on the larger, extinct species of crocodilians. Since crocodile anatomy has changed only slightly over the last 80 million years, current data on modern crocodilians can be used to estimate the bite force of extinct species. An 11-to-12-metre (36–39 ft) Deinosuchus would apply a force of 23,100 lbf (103,000 N), nearly twice that of the latest, higher bite force estimations of Tyrannosaurus (12,814 lbf (57,000 N)). The extraordinary bite of crocodilians is a result of their anatomy. The space for the jaw muscle in the skull is very large, which is easily visible from the outside as a bulge at each side. The muscle is so stiff, it is almost as hard as bone to touch, as if it were the continuum of the skull. Another trait is that most of the muscle in a crocodile's jaw is arranged for clamping down. Despite the strong muscles to close the jaw, crocodiles have extremely small and weak muscles to open the jaw. Crocodiles can thus be subdued for study or transport by taping their jaws or holding their jaws shut with large rubber bands cut from automobile inner tubes.
Locomotion
Crocodiles can move quickly over short distances, even out of water. The land speed record for a crocodile is 17 km/h (11 mph) measured in a galloping Australian freshwater crocodile. Maximum speed varies between species. Some species can gallop, including Cuban crocodiles, Johnston's crocodiles, New Guinea crocodiles, African dwarf crocodiles, and even small Nile crocodiles. The fastest means by which most species can move is a "belly run", in which the body moves in a snake-like (sinusoidal) fashion, limbs splayed out to either side paddling away frantically while the tail whips to and fro. Crocodiles can reach speeds of 10–11 km/h (6–7 mph) when they "belly run", and often faster if slipping down muddy riverbanks. When a crocodile walks quickly, it holds its legs in a straighter and more upright position under its body, which is called the "high walk". This walk allows a speed of up to 5 km/h.
Crocodiles may possess a homing instinct. In northern Australia, three rogue saltwater crocodiles were relocated 400 km (249 mi) by helicopter, but returned to their original locations within three weeks, based on data obtained from tracking devices attached to them.
Longevity
Measuring crocodile age is unreliable, although several techniques are used to derive a reasonable guess. The most common method is to measure lamellar growth rings in bones and teeth—each ring corresponds to a change in growth rate which typically occurs once a year between dry and wet seasons. Bearing these inaccuracies in mind, it can be safely said that all crocodile species have an average lifespan of at least 30–40 years, and in the case of larger species an average of 60–70 years. The oldest crocodiles appear to be the largest species. C. porosus is estimated to live around 70 years on average, with limited evidence of some individuals exceeding 100 years.
In captivity, some individuals are claimed to have lived for over a century. A male crocodile lived to an estimated age of 110–115 years in a Russian zoo in Yekaterinburg. Named Kolya, he joined the zoo around 1913 to 1915, fully grown, after touring in an animal show, and lived until 1995.[70] A male freshwater crocodile lived to an estimated age of 120–140 years at the Australia Zoo. Known affectionately as "Mr. Freshie", he was rescued around 1970 by Bob Irwin and Steve Irwin, after being shot twice by hunters and losing an eye as a result, and lived until 2010. Crocworld Conservation Centre, in Scottburgh, South Africa, claims to have a male Nile crocodile that was born in 1900. Named Henry, the crocodile is said to have lived in Botswana along the Okavango River, according to centre director Martin Rodrigues.
Social behaviour and vocalization
Crocodiles are the most social of reptiles. Even though they do not form social groups, many species congregate in certain sections of rivers, tolerating each other at times of feeding and basking. Most species are not highly territorial, with the exception of the saltwater crocodile, which is a highly territorial and aggressive species: a mature, male saltwater crocodile will not tolerate any other males at any time of the year, but most other species are more flexible. There is a certain form of hierarchy in crocodiles: the largest and heaviest males are at the top, having access to the best basking site, while females are priority during a group feeding of a big kill or carcass. A good example of the hierarchy in crocodiles would be the case of the Nile crocodile. This species clearly displays all of these behaviours. Studies in this area are not thorough, however, and many species are yet to be studied in greater detail. Mugger crocodiles are also known to show toleration in group feedings and tend to congregate in certain areas. However, males of all species are aggressive towards each other during mating season, to gain access to females.
Crocodiles are also the most vocal of all reptiles, producing a wide variety of sounds during various situations and conditions, depending on species, age, size and sex. Depending on the context, some species can communicate over 20 different messages through vocalizations alone. Some of these vocalizations are made during social communication, especially during territorial displays towards the same sex and courtship with the opposite sex; the common concern being reproduction. Therefore most conspecific vocalization is made during the breeding season, with the exception being year-round territorial behaviour in some species and quarrels during feeding. Crocodiles also produce different distress calls and in aggressive displays to their own kind and other animals; notably other predators during interspecific predatory confrontations over carcasses and terrestrial kills.
Specific vocalisations include —
Chirp: When about to hatch, the young make a "peeping" noise, which encourages the female to excavate the nest. The female then gathers the hatchlings in her mouth and transports them to the water, where they remain in a group for several months, protected by the female[76]
Distress call: A high-pitched call used mostly by younger animals to alert other crocodiles to imminent danger or an animal being attacked.
Threat call: A hissing sound that has also been described as a coughing noise.
Hatching call: Emitted by a female when breeding to alert other crocodiles that she has laid eggs in her nest.
Bellowing: Male crocodiles are especially vociferous. Bellowing choruses occur most often in the spring when breeding groups congregate, but can occur at any time of year. To bellow, males noticeably inflate as they raise the tail and head out of water, slowly waving the tail back and forth. They then puff out the throat and with a closed mouth, begin to vibrate air. Just before bellowing, males project an infrasonic signal at about 10 Hz through the water, which vibrates the ground and nearby objects. These low-frequency vibrations travel great distances through both air and water to advertise the male's presence and are so powerful they result in the water's appearing to "dance".
Reproduction
Crocodiles lay eggs, which are laid in either holes or mound nests, depending on species. A hole nest is usually excavated in sand and a mound nest is usually constructed out of vegetation. Nesting periods range from a few weeks up to six months. Courtship takes place in a series of behavioural interactions that include a variety of snout rubbing and submissive display that can take a long time. Mating always takes place in water, where the pair can be observed mating several times. Females can build or dig several trial nests which appear incomplete and abandoned later. Egg-laying usually takes place at night and about 30–40 minutes. Females are highly protective of their nests and young. The eggs are hard shelled, but translucent at the time of egg-laying. Depending on the species of crocodile, 7 to 95 eggs are laid. Crocodile embryos do not have sex chromosomes, and unlike humans, sex is not determined genetically. Sex is determined by temperature, where at 30 °C (86 °F) or less most hatchlings are females and at 31 °C (88 °F), offspring are of both sexes. A temperature of 32 to 33 °C (90 to 91 °F) gives mostly males whereas above 33 °C (91 °F) in some species continues to give males, but in other species resulting in females, which are sometimes called high-temperature females. Temperature also affects growth and survival rate of the young, which may explain the sexual dimorphism in crocodiles. The average incubation period is around 80 days, and also is dependent on temperature and species that usually ranges from 65 to 95 days. The eggshell structure is very conservative through evolution but there are enough changes to tell different species apart by their eggshell microstructure. Scutes may play a role in calcium storage for eggshell formation.
At the time of hatching, the young start calling within the eggs. They have an egg-tooth at the tip of their snouts, which is developed from the skin, and that helps them pierce out of the shell. Hearing the calls, the female usually excavates the nest and sometimes takes the unhatched eggs in her mouth, slowly rolling the eggs to help the process. The young is usually carried to the water in the mouth. She would then introduce her hatchlings to the water and even feed them. The mother would then take care of her young for over a year before the next mating season. In the absence of the mother crocodile, the father would act in her place to take care of the young. However, even with a sophisticated parental nurturing, young crocodiles have a very high mortality rate due to their vulnerability to predation. A group of hatchlings is called a pod or crèche and may be protected for months.
Cognition
Crocodiles possess some advanced cognitive abilities. They can observe and use patterns of prey behaviour, such as when prey come to the river to drink at the same time each day. Vladimir Dinets of the University of Tennessee, observed that crocodiles use twigs as bait for birds looking for nesting material. They place sticks on their snouts and partly submerge themselves. When the birds swooped in to get the sticks, the crocodiles then catch the birds. Crocodiles only do this in spring nesting seasons of the birds, when there is high demand for sticks to be used for building nests. Vladimir also discovered other similar observations from various scientists, some dating back to the 19th century. Aside from using sticks, crocodiles are also capable of cooperative hunting. Large numbers of crocodiles swim in circles to trap fish and take turns snatching them. In hunting larger prey, crocodiles swarm in, with one holding the prey down as the others rip it apart.
According to a 2015 study, crocodiles engage in all three main types of play behaviour recorded in animals: locomotor play, play with objects and social play. Play with objects is reported most often, but locomotor play such as repeatedly sliding down slopes, and social play such as riding on the backs of other crocodiles is also reported. This behaviour was exhibited with conspecifics and mammals and is apparently not uncommon, though has been difficult to observe and interpret in the past due to obvious dangers of interacting with large carnivores.
Taxonomy and phylogeny
See also: List of crocodilians
Crocodylidae is cladistically defined as a crown group composed of the last common ancestor of the Nile crocodile (Crocodylus niloticus), the Dwarf crocodile (Osteolaemus tetraspis), and all of its descendants. It contains two subfamilies: Crocodylinae and Osteolaeminae. Crocodylinae contains 13-14 living species, as well as 6 extinct species. Osteolaeminae was named by Christopher Brochu in 2003 as a subfamily of Crocodylidae separate from Crocodylinae and contains the two extant genera Osteolaemus and Mecistops, along with several extinct genera. The number of extant species within Osteolaeminae is currently in question.
Subfamily Crocodylinae
Genus Crocodylus
Crocodylus acutus, American crocodile
Crocodylus halli, Hall's New Guinea crocodile found South of the New Guinea Highlands
Crocodylus intermedius, Orinoco crocodile
Crocodylus johnsoni, freshwater crocodile, or Johnstone's crocodile
Crocodylus mindorensis, Philippine crocodile
Crocodylus moreletii, Morelet's crocodile or Mexican crocodile
Crocodylus niloticus, Nile crocodile or African crocodile (the subspecies found in Madagascar is sometimes called the black crocodile)
Crocodylus novaeguineae, New Guinea crocodile found North of the New Guinea Highlands
Crocodylus palustris, mugger, marsh or Indian crocodile
Crocodylus porosus, saltwater crocodile or estuarine crocodile
Crocodylus raninus, the Borneo crocodile, is currently considered to be a synonym of Crocodylus porosus; whether or not it is a distinct species remains unclear.
Crocodylus rhombifer, Cuban crocodile
Crocodylus siamensis, Siamese crocodile (may be extinct in the wild)
Crocodylus suchus, West African crocodile, desert or sacred crocodile
Crocodylus anthropophagus†
Crocodylus checchiai†
Crocodylus falconensis†
Crocodylus palaeindicus†
Crocodylus thorbjarnarsoni†
Genus Voay†
Voay robustus† (formerly Crocodylus robustus)
Subfamily Osteolaeminae
Genus Osteolaemus
Osteolaemus tetraspis, dwarf crocodile (There has been controversy as to whether or not this is actually two species; recent (2010) DNA analysis indicate three distinct species: O. tetraspis, O. osborni and a third, currently unnamed.)
Genus Mecistops
Mecistops cataphractus West African slender-snouted crocodile
Mecistops leptorhynchus Central African slender-snouted crocodile
Genus Brochuchus†
Brochuchus pigotti† (formerly Crocodylus pigotti)
Brochuchus parvidens†
Genus Euthecodon†
Euthecodon nitriae†
Euthecodon brumpti†
Euthecodon arambourgi†
Genus Rimasuchus†
Rimasuchus lloydi† (formerly Crocodylus lloydi)
Phylogeny
Recent molecular studies using DNA sequencing have shown crocodiles to be more closely related to the gavialids rather than to alligators, contrary to prior theories based on morphological studies alone.
Crocodilia
Alligatoridae
Caimaninae
Caiman
Melanosuchus
Paleosuchus
Alligatorinae
Alligator
Longirostres
Crocodylidae
Crocodylus
Mecistops
Osteolaemus
Gavialidae
Gavialis
Tomistoma
Mecistops cataphractus West African slender-snouted crocodile
Euthecodon†
Brochuchus†
Rimasuchus†
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
Crocodylinae
Voay†
Crocodylus
Crocodylus anthropophagus†
Crocodylus thorbjarnarsoni†
Crocodylus palaeindicus†
Crocodylus Tirari Desert†
Crocodylus johnstoni Freshwater crocodile
Crocodylus novaeguineae New Guinea crocodile
Crocodylus mindorensis Philippine crocodile
Crocodylus porosus Saltwater crocodile
Crocodylus siamensis Siamese crocodile
Crocodylus palustris Mugger crocodile
Crocodylus checchiai†
Crocodylus falconensis†
Crocodylus suchus West African crocodile
Crocodylus niloticus Nile crocodile
Crocodylus moreletii Morelet's crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
(crown group)
Crocodylidae
Osteolaeminae
Rimasuchus lloydi†
Voay robustus†
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
"Crocodylus" gariepensis†
Brochuchus parvidens†
Brochuchus pigotti†
Euthecodon arambourgi†
Euthecodon brumpti†
Crocodylinae
Mecistops cataphractus West African slender-snouted crocodile
Crocodylus thorbjarnarsoni†
Crocodylus anthropophagus†
Crocodylus niloticus Nile crocodile
Crocodylus checchiai†
Crocodylus moreletii Morelet's crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus palaeindicus†
Crocodylus palustris Mugger crocodile
Crocodylus ossifragus†
Crocodylus siamensis Siamese crocodile
Crocodylus mindorensis Philippine crocodile
Crocodylus johnstoni Freshwater crocodile
Crocodylus porosus Saltwater crocodile
Crocodylus raninus Borneo crocodile
Crocodylus novaeguineae New Guinea crocodile
Paleoafrican CrocodylusNeotropical CrocodylusIndo-Pacific Crocodylus
Relationship with humans
Danger to humans
Main article: Crocodile attacks
The larger species of crocodiles are very dangerous to humans, mainly because of their ability to strike before the person can react. The saltwater crocodile and Nile crocodile are the most dangerous, killing hundreds of people each year in parts of Southeast Asia and Africa. The mugger crocodile and American crocodile are also dangerous to humans.
Crocodile products
Further information: Crocodile farm and Crocodile skin
Crocodiles are protected in many parts of the world, but are also farmed commercially. Their hides are tanned and used to make leather goods such as shoes and handbags; crocodile meat is also considered a delicacy. The most commonly farmed species are the saltwater and Nile crocodiles, while a hybrid of the saltwater and the rare Siamese crocodile is also bred in Asian farms. Farming has resulted in an increase in the saltwater crocodile population in Australia, as eggs are usually harvested from the wild, so landowners have an incentive to conserve their habitat. Crocodile leather can be made into goods such as wallets, briefcases, purses, handbags, belts, hats, and shoes. Crocodile oil has been used for various purposes. Crocodiles were eaten by Vietnamese while they were taboo and off limits for Chinese. Vietnamese women who married Chinese men adopted the Chinese taboo.
Crocodile meat is consumed in some countries, such as Australia, Ethiopia, Thailand, South Africa, China, and Cuba (in pickled form). It is also occasionally eaten as an "exotic" delicacy in the western world. Cuts of meat include backstrap and tail fillet.
Due to high demand for crocodile products, TRAFFIC states that 1,418,487 Nile Crocodile skins were exported from Africa between 2006 and 2015.
Crocodile hunting and conservation
Aboriginal Australians harvested eggs and hunted crocodiles in a sustainable way for many thousands of years. The Brinkin people (aka Marrithiyal) of the Daly River in the Northern Territory (NT) used harpoons and bamboo, and even their own hands to capture crocodiles for food. After settlement of northern Australia, in the late-19th and early 20th centuries, non-Indigenous people killed individual crocodiles, mostly by locals to protect the population, or novelty-seeking visitors, or just opportunistically, so numbers were not noticeably reduced. From the 1930s, commercial hunting began, with Aboriginal people often employed to kill the crocodiles using traditional methods. From the 1940s to the 1960s, hunting began on a larger scale using .303 rifles. They were hunted for leather, with the skins shipped to plants in capital cities. Western Australia banned hunting freshwater crocodiles in 1962 and saltwater crocodiles in 1970, while NT bans were brought in 1964 and 1971; Queensland did not pass such legislation. The federal government later banned the export of crocodile skins, which brought commercial hunting to an end in Queensland. They have been a protected species since the 1970s, when numbers were down to approximately 3,000 in the NT at the lowest estimate. In 2021, after several attacks on humans by the "salties" and an estimated population of around 200,000 had been reached, Queensland politician Bob Katter called for the reintroduction of hunting.
In religion and mythology
Further information: Crocodilia § Cultural_depictions
Crocodiles have appeared in various forms in religions across the world. Ancient Egypt had Sobek, the crocodile-headed god, with his cult-city Crocodilopolis, as well as Taweret, the goddess of childbirth and fertility, with the back and tail of a crocodile. The Jukun shrine in the Wukari Federation, Nigeria is dedicated to crocodiles in thanks for their aid during migration. In Madagascar various peoples such as the Sakalava and Antandroy see crocodiles as ancestor spirits and under local fady often offer them food; in the case of the latter at least a crocodile features prominently as an ancestor deity.
Crocodiles appear in different forms in Hinduism. Varuna, a Vedic and Hindu god, rides a part-crocodile makara; his consort Varuni rides a crocodile.[88] Similarly the goddess personifications of the Ganga and Yamuna rivers are often depicted as riding crocodiles. Also in India, in Goa, crocodile worship is practised, including the annual Mannge Thapnee ceremony.
Sikh warriors known as nihang also have connections with crocodiles. Nihang may come from the Persian word for a mythical sea creature (Persian: نهنگ). The term owes its origin to Mughal historians, who compared the ferocity of the Akali with that of crocodiles. The meaning of Akali in Sikhism however, is the immortal army of Akal (god).
In Latin America, Cipactli was the giant earth crocodile of the Aztec and other Nahua peoples.
Fighting shark and crocodile, the emblem of Surabaya
The name of Surabaya,Indonesia, is locally believed to be derived from the words "suro" (shark) and "boyo" (crocodile), two creatures which, in a local myth, fought each other in order to gain the title of "the strongest and most powerful animal" in the area. It was said that the two powerful animals agreed for a truce and set boundaries; that the shark's domain would be in the sea while the crocodile's domain would be on the land. However one day the shark swam into the river estuary to hunt, this angered the crocodile, who declared it his territory. The Shark argued that the river was a water-realm which meant that it was shark territory, while the crocodile argued that the river flowed deep inland, so it was therefore crocodile territory. A ferocious fight resumed as the two animals bit each other. Finally the shark was badly bitten and fled to the open sea, and the crocodile finally ruled the estuarine area that today is the city. Another source alludes to a Jayabaya prophecy—a 12th-century psychic king of Kediri Kingdom—as he foresaw a fight between a giant white shark and a giant white crocodile taking place in the area, which is sometimes interpreted as a foretelling of the Mongol invasion of Java, a major conflict between the forces of the Kublai Khan, Mongol ruler of China, and those of Raden Wijaya's Majapahit in 1293. The two animals are now used as the city's symbol, with the two facing and circling each other, as depicted in a statue appropriately located near the entrance to the city zoo (see photo on the Surabaya page).[citation needed]
In language and as symbols
Main article: Crocodile tears
The term "crocodile tears" (and equivalents in other languages) refers to a false, insincere display of emotion, such as a hypocrite crying fake tears of grief. It is derived from an ancient anecdote that crocodiles weep in order to lure their prey, or that they cry for the victims they are eating, first told in the Bibliotheca by Photios I of Constantinople. The story is repeated in bestiaries such as De bestiis et aliis rebus. This tale was first spread widely in English in the stories of the Travels of Sir John Mandeville in the 14th century, and appears in several of Shakespeare's plays. In fact, crocodiles can and do generate tears, but they do not actually cry.
In the UK, a row of schoolchildren walking in pairs, or two by two is known as "crocodile".
Fashion logos
The French clothing company Lacoste features a crocodile in its logo. The American shoe company Crocs also uses this imagery in its logo.
The Asian elephant (Elephas maximus), also known as the Asiatic elephant, is the only living species of the genus Elephas and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, E. m. indicus from mainland Asia and E. m. sumatranus from the island of Sumatra. Formerly, there was also the Syrian elephant or Western Asiatic elephant (Elephas maximus asurus) which was the westernmost population of the Asian elephant (Elephas maximus). This subspecies became extinct in ancient times. Skeletal remains of E. m. asurus have been recorded from the Middle East: Iran, Iraq, Syria, and Turkey from periods dating between at least 1800 BC and likely 700 BC. It is one of only three living species of elephants or elephantids anywhere in the world, the others being the African bush elephant and African forest elephant. It is the second largest species of elephant after the African bush elephant.
The Asian elephant is the largest living land animal in Asia. Since 1986, the Asian elephant has been listed as Endangered on the IUCN Red List, as the population has declined by at least 50 per cent over the last three elephant generations, which is about 60–75 years. It is primarily threatened by loss of habitat, habitat degradation, fragmentation and poaching. In 2019, the wild population was estimated at 48,323–51,680 individuals. Female captive elephants have lived beyond 60 years when kept in semi-natural surroundings, such as forest camps. In zoos, Asian elephants die at a much younger age; captive populations are declining due to a low birth and high death rate.
The genus Elephas originated in Sub-Saharan Africa during the Pliocene and spread throughout Africa before expanding into the southern half of Asia. The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley civilisation dated to the 3rd millennium BC.
Evolution
The genus Elephas, of which the Asian elephant is the only living member, is the closest relative of the extinct mammoths. The two groups are estimated to have split from each other around 7 million years ago. The earliest Elephas species, Elephas ekorensis, is known from the Early Pliocene of East Africa, around 5-4.2 million years ago. The oldest remains of the genus in Asia are known from the Siwalik Hills in the Indian subcontinent, dating to the late Pliocene, around 3.6-3.2 million years ago, assigned to the species Elephas planifrons. The modern Asian elephant is suggested to have evolved from the species Elephas hysudricus, which first appeared at the beginning of the Early Pleistocene around 2.6 million years ago, and is primarily known from remains of Early-Middle Pleistocene age found on the Indian subcontinent.
In general, the Asian elephant is smaller than the African bush elephant and has the highest body point on the head. The back is convex or level. The ears are small with dorsal borders folded laterally. It has up to 20 pairs of ribs and 34 caudal vertebrae. The feet have five nail-like structures on each forefoot, and four on each hind foot. The forehead has two hemispherical bulges, unlike the flat front of the African elephants. Its long trunk or proboscis has only one fingerlike tip, in contrast to the African elephants which have two. Hence, the Asian species relies more on wrapping around a food item and squeezing it into its mouth, rather than grasping with the tip. Asian elephants have more muscle coordination and can perform more complex tasks.
Cows usually lack tusks; if tusks—in that case, called "tushes"—are present, they are barely visible and only seen when the mouth is open.[citation needed] The enamel plates of the molars are greater in number and closer together in Asian elephants. Some bulls may also lack tusks; these individuals are called "filsy makhnas", and are especially common among the Sri Lankan elephant population. A tusk from an 11 ft (3.4 m) tall elephant killed by Sir Victor Brooke measured 8 ft (2.4 m) in length, and nearly 17 in (43 cm) in circumference, and weighed 90 lb (41 kg). This tusk's weight is, however, exceeded by the weight of a shorter tusk of about 6 ft (1.8 m) in length which weighed 100 lb (45 kg), and there have reportedly been tusks weighing over 150 lb (68 kg).
Skin colour is usually grey, and may be masked by soil because of dusting and wallowing. Their wrinkled skin is movable and contains many nerve centres. It is smoother than that of African elephants and may be depigmented on the trunk, ears, or neck. The epidermis and dermis of the body average 18 mm (0.71 in) thick; skin on the dorsum is 30 mm (1.2 in) thick providing protection against bites, bumps, and adverse weather. Its folds increase surface area for heat dissipation. They can tolerate cold better than excessive heat. Skin temperature varies from 24 to 32.9 °C (75.2 to 91.2 °F). Body temperature averages 35.9 °C (96.6 °F).
Size
On average, when fully-grown, bulls are about 2.75 m (9.0 ft) tall at the shoulder and 4.0 t (4.4 short tons) in weight, while cows are smaller at about 2.40 m (7.9 ft) at the shoulder and 2.7 t (3.0 short tons) in weight. Sexual dimorphism in body size is relatively less pronounced in Asian elephants than in African bush elephants; with bulls averaging 15% and 23% taller in the former and latter respectively. Length of body and head including trunk is 5.5–6.5 m (18–21 ft) with the tail being 1.2–1.5 m (3.9–4.9 ft) long. The largest bull elephant ever recorded was shot by the Maharajah of Susang in the Garo Hills of Assam, India, in 1924, it weighed an estimated 7 t (7.7 short tons), stood 3.43 m (11.3 ft) tall at the shoulder and was 8.06 m (26.4 ft) long from head to tail. There are reports of larger individuals as tall as 3.7 m (12 ft).
Asian elephants inhabit grasslands, tropical evergreen forests, semi-evergreen forests, moist deciduous forests, dry deciduous forests and dry thorn forests, in addition to cultivated and secondary forests and scrublands. Over this range of habitat types elephants occur from sea level to over 3,000 m (9,800 ft). In the eastern Himalaya in northeast India, they regularly move up above 3,000 m (9,800 ft) in summer at a few sites.
In China, the Asian elephant survives only in the prefectures of Xishuangbanna, Simao, and Lincang of southern Yunnan. The estimated population is around 300 individual (in 2020).
In Bangladesh, some isolated populations survive in the south-east Chittagong Hills.[10] A herd of 20–25 wild elephants was reported as being present in the Garo Hills of Mymensingh in the late-1990s, being detached from a big herd in the Peack hills of India and prevented from returning by fences put up in the meantime by the Indian border security force. The herd was estimated at about 60 individuals in 2014.
In Malaysia's northern Johor and Terengganu National Park, two Asian elephants were tracked using satellite tracking technology. They spent most of their time in secondary or "logged-over forest" and travelled 75% of their time in an area less than 1.5 km (0.93 mi) away from a water source.
Asian elephants are crepuscular. They are classified as megaherbivores and consume up to 150 kg (330 lb) of plant matter per day. They are generalist feeders, and are both grazers and browsers. They are known to feed on at least 112 different plant species, most commonly of the order Malvales, as well as the legume, palm, sedge and true grass families. They browse more in the dry season with bark constituting a major part of their diet in the cool part of that season. They drink at least once a day and are never far from a permanent source of fresh water.They need 80–200 litres of water a day and use even more for bathing. At times, they scrape the soil for clay or minerals.
Cows and calves move about together as groups, while bulls disperse from their mothers upon reaching adolescence. Bulls are solitary or form temporary "bachelor groups". Cow-calf units generally tend to be small, typically consisting of three adults (most likely related females) and their offspring. Larger groups of as many as 15 adult females have also been recorded. Seasonal aggregations of 17 individuals including calves and young adults have been observed in Sri Lanka's Uda Walawe National Park. Until recently, Asian elephants, like African elephants, were thought to be under the leadership of older adult females, or matriarchs. It is now recognized that cows form extensive and very fluid social networks, with varying degrees of associations between individuals. Social ties generally tend to be weaker than in African elephants.
Unlike African elephants, which rarely use their forefeet for anything other than digging or scraping soil, Asian elephants are more agile at using their feet in conjunction with the trunk for manipulating objects. They can sometimes be known for their violent behavior.
Asian elephants are recorded to make three basic sounds: growls, squeaks and snorts. Growls in their basic form are used for short distance communication. During mild arousal, growls resonate in the trunk and become rumbles while for long-distance communication, they escalate into roars. Low-frequency growls are infrasonic and made in many contexts. Squeaks come in two forms: chirpings and trumpets. Chirping consists of multiple short squeaks and signals conflict and nervousness. Trumpets are lengthened squeaks with increased loudness and are produced during extreme arousal. Snorts signal changes in activity and increase in loudness during mild or strong arousal. During the latter case, when an elephant bounces the tip of the trunk, it creates booms which serve as threat displays: 142 Elephants can distinguish low-amplitude sounds.
Rarely, tigers have been recorded attacking and killing calves, especially if the calves become separated from their mothers, stranded from their herd, or orphaned. Adults are largely invulnerable to natural predation. There is a singular anecdotal case of a mother Asian elephant allegedly being killed alongside her calf; however, this account is contestable. In 2011 and 2014, two instances were recorded of tigers successfully killing adult elephants; one by a single tiger in Jim Corbett National Park on a 20-year-old young adult elephant cow, and another on a 28-year-old sick adult bull in Kaziranga National Park further east, which was taken down and eaten by several tigers hunting cooperatively. Elephants appear to distinguish between the growls of larger predators like tigers and smaller predators like leopards; they react to leopards less fearfully and more aggressively.
Reproduction in Asian elephants can be attributed to the production and perception of signaling compounds called pheromones. These signals are transmitted through various bodily fluids. They are commonly released in urine but in males they are also found in special secretions from the temporal glands. Once integrated and perceived, these signals provide the receiver with information about the reproductive status of the sender. If both parties are ready to breed, reproductive ritualic behavior occurs and the process of sexual reproduction proceeds.
Bulls will fight one another to get access to oestrus cows. Strong fights over access to females are extremely rare. Bulls reach sexual maturity around the age of 12–15. Between the ages of 10 and 20 years, bulls undergo an annual phenomenon known as "musth". This is a period where the testosterone level is up to 100 times greater than non-musth periods, and they become aggressive. Secretions containing pheromones occur during this period, from the paired temporal glands located on the head between the lateral edge of the eye and the base of the ear. The aggressive behaviors observed during musth can be attributed to varying amounts of frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane) throughout the maturation process of bulls. Frontalin is a pheromone that was first isolated in bark beetles but can also be produced in the bulls of both Asian and African Elephants. The compound can be excreted through urine as well as through the temporal glands of the bull, allowing signaling to occur. During musth, increased concentrations of frontalin in the bull's urine communicate the reproductive status of the bull to female elephants.
Similar to other mammals, hormone secretion in female elephants is regulated by an estrous cycle. This cycle is regulated by surges in Luteinizing Hormone that are observed 3 weeks from each other. This type of estrous cycle has also been observed in African Elephants but is not known to affect other mammals. The first surge in Luteinizing Hormone is not followed by the release of an egg from the ovaries. However, some female elephants still exhibit the expected mating protocols during this surge. Female elephants give ovulatory cues by utilizing sex pheromones. A principal component thereof, (Z)-7-dodecen-1-yl acetate, has also been found to be a sex pheromone in numerous species of insects. In both insects and elephants, this chemical compound is used as an attractant to assist the mating process. In elephants, the chemical is secreted through urination and this aids in the attraction of bulls to mate. Once detected, the chemical stimulates the vomeronasal organ of the bull, thus providing information on the maturity of the female.
Reproductive signaling exchange between male and female elephants are transmitted through olfactory cues in bodily fluids. In males, the increase in frontalin during musth heightens their sensitivity to the (Z)-7-dodecen-1-yl acetate produced by female elephants. Once perceived by receptors in the trunk, a sequence of ritualistic behaviors follow. The responses in males vary based on both the stage of development and the temperament of the elephant. This process of receiving and processing signals through the trunk is referred to as flehmen. The difference in body movements give cues to gauge if the male is interested in breeding with the female that produced the secretion. A bull that is ready to breed will move closer to the urine and in some cases an erection response is elicited. A bull that is not ready to breed will be timid and try to dissociate themselves from the signal.
In addition to reproductive communication, chemosensory signaling is used to facilitate same-sex interactions. When less developed males detect pheromones from a male in musth, they often retreat to avoid coming in contact with aggressive behaviors. Female elephants have also been seen to communicate with each other through pheromone in urine. The purpose of this type of intersex communication is still being investigated. However, there are clear differences in signaling strength and receiver response throughout different stages of the estrous cycle.
The gestation period is 18–22 months, and the cow gives birth to one calf, only occasionally twins. The calf is fully developed by the 19th month, but stays in the womb to grow so that it can reach its mother to feed. At birth, the calf weighs about 100 kg (220 lb), and is suckled for up to three years. Once a female gives birth, she usually does not breed again until the first calf is weaned, resulting in a four to five-year birth interval. During this period, mother to calf communication primarily takes place through temporal means. However, male calves have been known to develop sex pheromone-producing organs at a young age. Early maturity of the vomeronasal organ allows immature elephants to produce and receive pheromones. It is unlikely that the integration of these pheromones will result in a flehmen response in a calf. Females stay on with the herd, but mature males are chased away.
Female Asian elephants sexually mature around the age of 10~15 and keep growing until 30, while males fully mature at more than the age of 25, and constantly grow throughout their life. Average elephant life expectancy is 60 years in the wild and 80 in captivity, although this has been exaggerated in the past. Generation length of the Asian elephant is 22 years.
Asian elephants have a very large and highly developed neocortex, a trait also shared by humans, apes and certain dolphin species. They have a greater volume of cerebral cortex available for cognitive processing than all other existing land animals.[citation needed] Results of studies indicate that Asian elephants have cognitive abilities for tool use and tool-making similar to great apes. They exhibit a wide variety of behaviours, including those associated with grief, learning, allomothering, mimicry, play, altruism, use of tools, compassion, cooperation, self-awareness, memory, and language. Elephants reportedly head to safer ground during natural disasters like tsunamis and earthquakes, but data from two satellite-collared Sri Lankan elephants indicate this may be untrue.
Several students of elephant cognition and neuroanatomy are convinced that Asian elephants are highly intelligent and self-aware. Others contest this view.
Threats
The pre-eminent threats to the Asian elephant today are the loss, degradation and fragmentation of its habitat, which leads to increasing conflicts between humans and elephants. Asian elephants are poached for ivory and a variety of other products including meat and leather. The demand for elephant skin has risen due to it being an increasingly-common ingredient in traditional Chinese medicine.
Human–elephant conflict
In some parts of Asia, people and elephants have co-existed for thousands of years. In other areas, people and elephants come into conflict, resulting in violence, and ultimately, the displacement of elephants.
Destruction of forests through logging, encroachment, slash-and-burn, shifting cultivation, and monoculture tree plantations are major threats to the survival of elephants. Human–elephant conflicts occur when elephants raid crops of shifting cultivators in fields, which are scattered over a large area interspersed with forests. Depredation in human settlements is another major area of human–elephant conflict occurring in small forest pockets, encroachments into elephant habitat, and on elephant migration routes. However, studies in Sri Lanka indicate that traditional slash-and-burn agriculture may create optimal habitat for elephants by creating a mosaic of successional-stage vegetation. Populations inhabiting small habitat fragments are much more liable to come into conflict with humans.
Human-elephant conflict can be categorised into:
ultimate causes including growing human population, large-scale development projects and poor top-down governance;
proximate causes including habitat loss due to deforestation, disruption of elephant migratory routes, expansion of agriculture and illegal encroachment into protected areas.
Development such as border fencing along the India–Bangladesh border has become a major impediment to the free movement of elephants. In Assam, more than 1,150 humans and 370 elephants died as a result of human-elephant conflict between 1980 and 2003. In India alone, over 400 people are killed by elephants every year, and 0.8 to 1 million hectares are damaged, affecting at least 500,000 families across the country. Moreover, elephants are known to destroy crops worth up to US$2–3 million annually. This has major impacts on the welfare and livelihoods of local communities, as well as the future conservation of this species. In countries like Bangladesh and Sri Lanka, the Asian elephant is one of the most feared wild animals, even though they are less deadly than other local animals such as venomous snakes (which were estimated to claim more than 30 times more lives in Sri Lanka than elephants). As a whole, Asian elephants display highly sophisticated and sometimes unpredictable behaviour. Most untamed elephants try to avoid humans, but if they are caught off guard by any perceived physical threat, including humans, they will likely charge. This is especially true of males in musth and of females with young. Gunfire and other similar methods of deterring, which are known to be effective against many kinds of wild animals including tigers, may or may not work with elephants, and can even worsen the situation. Elephants that have been abused by humans in the past often become "rogue elephants", which regularly attack people with no provocation.
Poaching
For ivory
The demand for ivory during the 1970s and 1980s, particularly in East Asia, led to rampant poaching and the serious decline of elephants in both Africa and Asia. In Thailand, the illegal trade in live elephants and ivory still flourishes. Although the amount of ivory being openly sold has decreased substantially since 2001, Thailand still has one of the largest and most active black markets for ivory seen anywhere in the world. Tusks from Thai-poached elephants also enter the market; between 1992 and 1997 at least 24 male elephants were killed for their tusks.
Up to the early 1990s, Vietnamese ivory craftsmen used exclusively Asian elephant ivory from Vietnam and neighbouring Lao and Cambodia. Before 1990, there were few tourists and the low demand for worked ivory could be supplied by domestic elephants. Economic liberalisation and an increase in tourism raised both local and visitors' demands for worked ivory, which resulted in heavy poaching.
For skin
The skin of the Asian elephant is used as an ingredient in Chinese medicine as well as in the manufacture of ornamental beads. The practice has been aided by China's State Forestry Administration (SFA), which has issued licences for the manufacture and sale of pharmaceutical products containing elephant skin, thereby making trading legal. In 2010, four skinned elephants were found in a forest in Myanmar; 26 elephants were killed by poachers in 2013 and 61 in 2016. According to the NGO Elephant Family, Myanmar is the main source of elephant skin, where a poaching crisis has developed rapidly since 2010.
Handling methods
Young elephants are captured and illegally imported to Thailand from Myanmar for use in the tourism industry; calves are used mainly in amusement parks and are trained to perform various stunts for tourists.
The calves are often subjected to a 'breaking in' process, which may involve being tied up, confined, starved, beaten and tortured; as a result, two-thirds may perish. Handlers use a technique known as the training crush, in which "handlers use sleep-deprivation, hunger, and thirst to "break" the elephants' spirit and make them submissive to their owners"; moreover, handlers drive nails into the elephants' ears and feet.
Disease
The Asian elephant is listed on CITES Appendix I. It is a quintessential flagship species, deployed to catalyze a range of conservation goals, including habitat conservation at landscape scales, generating public awareness on conservation issues, and mobilisation as a popular cultural icon both in India and the West. A key aspect of Asian elephant conservation is connectivity, and preserving the preferred movement routes of elephants through areas of high vegetation cover and with "low human population density".
The World Elephant Day has been celebrated on 12 August since 2012. Events are organized to divulge information and to engage people about the problems that the Asian elephant is facing. August has been established as the Asian Elephant Awareness Month by zoos and conservation partners in the United States.
In China, Asian elephants are under first-level protection. Yunnan province has 11 national and regional nature reserves. In total, the covered protected area in China is about 510,000 km2 (200,000 sq mi). In 2020, the population of Asian elephants in Yunnan was estimated at around 300 individuals. As conflicts between humans and wild elephants have emerged around protected areas in the last years, the prefecture of Xishuangbanna built food bases and planted bananas and bamboo to create a better habitat.
In Thailand, Salakpra Wildlife Sanctuary and Tham Than Lot National Park are protected areas hosting around 250–300 elephants, according to figures from 2013. In recent years the National Park has faced issues due to encroachment and over-exploitation.
In India, the National Board of Wildlife did a recommendation, allowing coal mining in the Dehing Patkai elephant reserve in April 2020. The decision raised concerns between students and environmental activists who launched an online campaign to stop the project.
In captivity
About half of the global zoo elephant population is kept in European zoos, where they have about half the median life span of conspecifics in protected populations in range countries. This discrepancy is clearest in Asian elephants: infant mortality is twice that seen in Burmese timber camps, and adult survivorship in zoos has not improved significantly in recent years. One risk factor for Asian zoo elephants is being moved between institutions, with early removal from the mother tending to have additional adverse effects. Another risk factor is being born into a zoo rather than being imported from the wild, with poor adult survivorship in zoo-born Asians apparently being conferred prenatally or in early infancy. Likely causes for compromised survivorship is stress and/or obesity. Foot problems are commonly observed in captive elephants. These are related to lack of exercise, long hours standing on hard substrates, and contamination resulting from standing in their dung. Many of these problems are treatable. However, mistreatment may lead to serious disability or death.
Demographic analysis of captive Asian elephants in North America indicates that the population is not self-sustaining. First year mortality is nearly 30 per cent, and fecundity is extremely low throughout the prime reproductive years. Data from North American and European regional studbooks from 1962 to 2006 were analysed for deviations in the birth and juvenile death sex ratios. Of 349 captive calves born, 142 died prematurely. They died within one month of birth, major causes being stillbirth and infanticide by either the calf's mother or by one of the exhibition mates. The sex ratio of stillbirths in Europe was found to have a tendency for excess of males.
In culture
Bones of Asian elephants excavated at Mohenjo-daro in the Indus Valley indicate that they were tamed in the Indus Valley civilization and used for work. Decorated elephants are also depicted on seals and were modelled in clay.
The Asian elephant became a siege engine, a mount in war, a status symbol, a beast of burden, and an elevated platform for hunting during historical times in South Asia.
Asian elephants have been captured from the wild and tamed for use by humans. Their ability to work under instruction makes them particularly useful for carrying heavy objects. They have been used particularly for timber-carrying in jungle areas. Other than their work use, they have been used in war, in ceremonies, and for carriage. It is reported that war elephants are still in use by the Kachin Independence Army (KIA) to take control of Kachin State in northern Myanmar from Myanmar's military. The KIA use about four dozen elephants to carry supplies.
The Asian elephant plays an important part in the culture of the subcontinent and beyond, being featured prominently in the Panchatantra fables and the Buddhist Jataka tales. They play a major role in Hinduism: the god Ganesha's head is that of an elephant, and the "blessings" of a temple elephant are highly valued. Elephants are frequently used in processions where the animals are adorned with festive outfits.
The Asian elephant is depicted in several Indian manuscripts and treatises. Notable amongst these is the Matanga Lila (elephant sport) of Nilakantha. The manuscript Hastividyarnava is from Assam in northeast India.
In the Burmese, Thai and Sinhalese animal and planetary zodiac, the Asian elephant, both tusked and tuskless, are the fourth and fifth animal zodiacs of the Burmese, the fourth animal zodiac of the Thai, and the second animal zodiac of the Sinhalese people of Sri Lanka. Similarly, the elephant is the twelfth animal zodiac in the Dai animal zodiac of the Dai people in southern China.
Unissaan he lukevat enemmän kuin puhuvat.
Vapaa Taidekoulu lopputyö 2018
Free Art School Graduation Exhibition 2018
akryyli ja öljyväri kankaalle, 130x150cm
"I was born into this body - through it I create a connection with reality. My body paints, all the experiences in me, the whole intellectual cognition.
In the kinesphere I extend in my ideas as far as I want, I free myself from my introvert's world. It's fascinating and self-contradictory. I look at the world as a researcher, but I reflect knowledge through art."
-Maarit Rantala
I hear my PSY 304 professor going on about affect, behavior, and cognition down the hall as I take a break to watch the world 12 hours after the VT tragedy.
First of all, it is important to know that the Kutubiah is not built by chance at this place: indeed, there are flows of the 7 metals that criss-cross the Earth like meridians. The Kutubiah is at the crossroads of two simple gold streams, one North-South passing through Santiago, Tomar and Marrakesh. An east-west flow passes through Damascus, Gardaïa and Marrakesh. The tower is therefore a scalar wave sensor. The rest is a parallel with experiments carried out in Ireland on identical towers and in India. The metal balls are like tachyon energy sensors or organ cannons.
Physics used to teach us that space is a kind of absolute container, separate from the flow of time. In this classical or Newtonian conception, objects traveled through or remained stationary in space, which itself was not subject to change or to internal variations. The three dimensions of space were the same, always and everywhere. Galileo's observation of the moons of Jupiter would eventually lead to the fundamental assertion, so damaging to the prevailing Christian or traditional cosmology of the time, that in fact the laws down here on earth and the laws up there in the heavens are the very same. Our "space" as we experience it on earth, according to its inviolable coordinates of width, height, and depth, or the famous x, y, and z of the Cartesian coordinate system exists uniformly throughout the universe and is governed by the same rules. With the dismissal of the ether (the fifth element the celestial spheres were thought to be made of) and the adoption of an atomist theory, the physical vision of the universe was one of billiard balls colliding in a uniform and static vacuum, with things like electromagnetism and thermal energy thrown into the mix.
www.ibnarabisociety.org/articles/timeofscience.html
In this conception, time was a measure and nothing more, and was itself assumed to be constant and unchanging. One used time in frequency and velocity values, but time itself had nothing essentially to do with the nature of space and certainly nothing to do with physical objects themselves. The great paradigm shift in physics came with Einstein's special theory of relativity, which was later to be expanded upon in his general theory of relativity. In addition to showing that there is no absolute frame of reference for physical measurements, the theory also demonstrated mathematically that what we ordinarily think of as space and time are actually intertwining realities – or two aspects of the same reality. How we move through space changes how we move through time, at least depending on the point of observation. If I travel from Earth for a period of time near the speed of light and then return, a much longer period of time will have elapsed from Earth's frame of reference than will have elapsed from my own frame of reference, in some sort of space vehicle for example. Time also changes depending on how close I am to a strong gravitational field. A clock in orbit high above the earth, for example, will run slightly slower than an identical clock on the surface of the earth.
Now, many books have been written in the last few decades claiming that the teachings of Eastern religions such as Buddhism and the finding of modern physics, specifically quantum mechanics and relativity theory, are really the same, and much is made of the spiritual significance of this new physics.2 Though it is a topic for another forum, I believe that the perceived intersection of physics and mysticism or religion results from a sublimation of certain hypothetical assumptions of physical data on the one hand, and a denaturing of the spiritual doctrines on the other. That is to say, certain interpretations of the physical data, such as the idea that the observer influences the state vector collapse, and the notion of multiple universes arising out of the actualization of the wave function of particles, are nothing more than philosophical struggles on the part of physicists and laymen to come to grips with the data. They are not demanded by the data themselves, which is why many physicists who agree on the same data have sometimes wildly different models for accounting for those data.3 On the religious side, one comes across pat explanations of spiritual doctrines taken out of their traditional context, and Buddhism is reduced to a group of clever insights about our mind and the nature of the world.
Thus I want to be careful of including the findings of physics in a paper on the experience of time and non-time at a conference on Ibn al-'Arabī. I may joyously proclaim that Ibn al-'Arabī told us in the thirteenth century what physicists claim to have discovered only a few decades ago, but what happens when the scientists change their minds? After all, despite what the popular literature and movies tell us, there are enormous lacunae in physics, and for all we know the spatio-temporal conception ushered in by Einstein may one day itself be overturned by something as radically different. To give you some examples, quantum mechanics works for very small things, and relativity works for very big things, but at a certain point in between, for medium sized things, the theories become incompatible. This was the problem with Newtonian or classical physics: for many purposes the theory worked just fine, but physicists were puzzled because it did not work for all observed phenomena. Thus Newtonian equations will correctly predict how a baseball will travel through space, but it took relativity to correctly account for the orbit of the planet Mercury. Our present idea of gravity and the mass of the universe should have the universe flying apart, but since it does not actually do so, physicists posit dark matter, which accounts for 98 percent of the mass of the universe. The problem is since we cannot see or measure this dark matter, we do not know what it is, or really if it is there.
So why start a discussion of time at an Ibn 'Arabī Society gathering with physics? Firstly, despite the fact that classical physics is part of history as far as scientists are concerned, its world view still dominates the consciousness of the age. It is what is most typically taught in high school textbooks, and its assumptions are built into popular language about the subject. The next time you hear someone say "fundamental building blocks of matter" know that such a notion is completely classical in its origin. All our notions of mass, force, and energy are usually classical conceptions, that is to say conceptions beginning from the bifurcation of the world into measurable and subjective knowledge by Descartes, then Galileo's uniformity of the universal laws, and finally Newton's brilliant synthesis. Moreover, these ideas, together with the advent of the heliocentric model, was a major force, perhaps the most important force, in sidelining Christianity in the Western world. First the Church abdicated its claim to having knowledge of the natural world, and while it spent the next few centuries in the domain of moral and spiritual questions, scientists gradually reduced the world to physical bits, reduced man to a hyper developed animal, reduced animals to complex arrangements of atoms, and reduced consciousness to complex patterns of synaptic activity in the brain. Meanwhile the philosophers and pseudo-philosophers of scientism were busy trying to convince themselves and everyone else that truth was provided only by quantitative measurement. The rest was quality, which fell on the side of subjective feeling, and as we all were supposed to know, feelings are really just complex instincts, which somehow result from the structure of the brain, resulting from the structure of DNA, resulting from the happenstance arrangement of atoms.
Relativity theory and quantum mechanics overturned classical mechanics, which had itself overturned Christian cosmology. The paradigm shift ushered in by such figures as Einstein, Max Planck, and Neils Bohr is important because it destroyed the destroyer. Heliocentrism was erased, because from the point of view of relativity it is nonsense to say that the earth "goes round" the sun, as it is to say that the sun goes round the earth, because there is no fixed frame of reference to say which is going around which. The sun's gravitational field is stronger than the earth's, but the earth does pull on the sun, and because there is no absolute frame of reference anymore, then certainly it is correct to say the sun goes around the earth. Geocentrism actually comes out slightly ahead, since it at least corresponds to our experience from our frame of reference. From the point of view of science, however, we have lost both geocentrism and heliocentrism.
As for universal laws, we find that things do not behave the same everywhere. For example a clock seems to run at a different speed high above the earth. Light does not always travel in a straight line, but seems to bend from different points of reference, because space itself seems to bend and take on all sorts of shapes depending on the objects in it.
Then we discover that atoms are not mere little balls. Rather, it seems the only way we can properly describe what seems to be happening on very small scales is through various kinds of mathematical form, very unlike a little ball. The only reason scientists talk about wave-particle duality is because the measurements they get look sometimes like a particle, sometimes like a wave, but they never have nor ever will see what causes those measurements. The relationships between the "atoms" is mathematically incredibly complex and is more like threads in a tapestry than balls flying through space, but of course they are neither. The problem is further complicated by Bell's theorem, which shows entities like electrons to be connected, as far as we can tell, instantaneously even at distances too great for a light-speed communication to take place. This is important because relativity theory states that nothing can travel faster than the speed of light.
Thus the momentousness of heliocentrism, atomist theory, uniformity of spatial laws and time was shown to be not so momentous after all, but this is lost on popular thinking. Einstein certainly earned his own fame but did not manage to steal all of Newton's thunder. The most usual understanding of the natural world is still a classical one.
But I already cautioned myself about too great an enthusiasm for what the new physics teaches. Indeed it may be that the current paradigm is overturned, but it seems well-nigh impossible that any such a revolution will bring us closer to the classical conception that destroyed traditional cosmology in the West. We have already pushed the limits of what we can actually observe with our own senses, which is to say anything else we observe will be the effects of experiments together with the mathematical models based on the data of those experiments. Physicists' eyes are not more powerful than our own; their insight comes through the mathematical form they derive from the data. Such mathematical models are the very stuff of physical theory.
The significance of this is not that it elevates one theoretical model above another, but that it throws into sharp focus the fact that any model of what happens beyond the perceptible world is as good as any other from the point of view of science, so long as it correctly predicts the data. The problem with superstring theory, hidden variable theory, many-universe theory, is that they are all mathematical models based upon the exact same body of data, and they all predict the data equally well. These models are sometimes so wildly different that any pretense to some one great scientific conception of the universe must be seen as philosophical hubris. The precision of the data themselves and the success of the accompanying mathematics in predicting the behavior of the physical world on small and large scales – indeed the most successful scientific theory to date – paradoxically serves to undercut the assumption that the only real knowledge we can have of things is through scientific measurement. What we are measuring are things we can never perceive without a measurement. Classical mechanics usually dealt with ordinary scale objects. If the real knowledge we have of a baseball is the measurements we can make of it, we are still left with an object that at least corresponds to an object we actually experience, even if that experience is merely subjective or even meaningless from the point of view of science. An electron is an entity no one has, can, or ever will experience. Even if we never perceive a unicorn in fact, we could in principle.
The key reversal at play is the following: we measure quantum entities, but our knowledge of them is mediated completely by our ordinary experience of the world, by our pointer-readings, as Wittgenstein once remarked. I said that the new physics paradoxically undercuts classical bifurcation because it leaves us with the troubling proposition that our true scientific knowledge depends for its very survival upon the offices of our subjective, non-scientific experience. Actually, this was the case in classical mechanics as well, but the fact that quantum entities are wholly unlike ordinary entities makes the rigid bifurcation into a subjective world of quality and an objective world of quantity all the more absurd.4
The situation we are left with is this. The revolution of classical mechanics suffered a counter-revolution, the new physics, which neutralized the sting delivered by the heliocentric model, uniform space and time, and the classical atomist theory. Though this counter-revolution did not put traditional cosmology back in its place, it robbed the scientist of his ability to make absolute statements about what we can know. A man might be lulled into a kind of complacency about the baseball; perhaps the knowledge provided by scientific measurement is more true and reliable than his mere experience of the thing. This may not hold up to philosophical scrutiny, but overlap between the measured baseball and a baseball as one sees it gives the whole affair an air of respectability. But when the scientist tells us that true knowledge is measuring things that we cannot see, and that the scientist cannot see either, it begins to sound too strange to be believed. And of course, it is.
So unlike many of the popular ideas linking the new physics to traditional metaphysics, my assertion here is simply that science has exposed the fallacy of Cartesian bifurcation and the alleged supremacy of quantitative knowledge. Science has turned on itself, or more correctly, the data has betrayed philosophical scientism and exposed its limitations. We have quite literally come back to our senses.
If we actually pay attention to the difference between quantitative data and physical theory, we see that science has altogether lost the destructive power to make us denigrate our senses and the ideas we form from sensory experience. We know that what the scientist says about time is a model based on observations of the world, and that any number of such models possess equal validity, and all of them are subservient to the real experience of the human subject. Choosing one model above another is not a scientific decision, but a philosophical one.
Time, like space, is one of the most concrete aspects of our experience of the world. It is not an abstract entity such as an electron, but a reality so close and intimate that we stumble in defining it owing to its sheer obviousness. It is a mystery that baffles due to its clarity, not its obscurity. If a physicist says that time is not what we think but is actually this or that, we can agree in part and acknowledge that the reality may have aspects of which we are not aware. However, we always possess the powerful rejoinder that no matter what the data or theory, it has been formed on the basis of the physicist's ordinary human experience of time and observations taking place within that experience. Logically, it is impossible to negate the qualitative time of our own experience without undercutting the basis of the quantitative time derived through measurement, since no observation is possible without ordinary time and ordinary space. "Reification" is the problem we get when we put our theories of quantitative time above qualitative time in our hierarchy of knowledge. I may give a mathematical description of time utilizing perhaps a symbolic or allegorical use of geometric shapes, but then become trapped in my own provisional model. Even the word "linear" in linear time is a model. We make an analogy of some property of our experience of time to the properties of a physical line in space, i.e., being continuous and existing in two directions. But time is not a line, a line is a line. Having used the image of a line to enable us to talk about time in a scientifically useful way, we get trapped by an image which has taken on a life of its own, so to speak. Then anything other than linear time begins to seem absurd, a violation of time the way a loop is a violation of a line.
The Cartesian bifurcation which elevates quantitative measurement and theory while denigrating the real experience of qualities is ultimately absurd, because no model can repudiate the model-maker and continue to remain meaningful. It would mean that the model-maker's knowledge of what he is making a model of is dependent upon the knowledge provided by that very model itself. A bifurcationist physicist discerns a mathematical form in the data of the world, then says that this mathematical form is more true than the very perception he used to discern that mathematical form. If by this he meant that the world manifests laws present in the Intellect or Great Spirit, we could agree, since we perceive those laws by virtue of participating in that same intellect. But that is not an idea the philosophers of scientism would be willing to entertain.
Let me now leave off the space-time continuum of physics and come to the soul's qualitative and lived experience of these realities we call space and time. Space and time appear to us to be two modes of extension, or in simpler terms two ways in which things are spread out in relationship to each other. Spatially things are here and there, and temporally things are before and after. In another essay I discussed at length this notion of space and time as extension, and I do not wish to duplicate that discussion here.5 My purpose here is to establish a link between space and time that is not at all based on relativity theory, but arises from our living experience. Although in the classical conception which so often dominates our minds space and time are seen as two separate and unlike things, the truth is that time is impossible without space, and space is impossible without time. I do not make this assertion from the point of view of physical science, but from within the world of the metaphysics of Ibn al-'Arabī and similar metaphysical systems.
Let us first ask what the world would be like if there were only space, but no time. The first thing that we would notice is that change would become impossible. Think of a group of objects existing in space, and then think of them existing in a different arrangement. In order for them to go from the first arrangement to the second one, something has to happen. They have to at the very least traverse the distances necessary to arrive at the second arrangement, but how can they do that if there is only space and no time? Something has to ontologically link the two arrangements. Even if somehow they do not traverse the distance in between, the objects are still the same objects, and the only thing allowing us to call them the same objects in the two different arrangements is a reality that allows the objects to change but retain some kind of continuity. This connecting dimension is time.
Let us then ask what the world would be like if there were time but no space. Since there would be no spatial extension to observe, we would somehow have to measure time with our subjective experience in the absence of height, width, and depth. How would we know that there even was a course of time? Feelings have no dimension perhaps, but what about the rest of the soul? The images in our imagination, never mind the objects of the objective world, all have spatial extension, so we would have to disallow them in a world without space. That is to say, time implies a kind of inward space in the soul – a different kind of space to be sure – that makes it meaningful to speak of before and after, a referent that is constant in the face of change.
Let us as an exercise try to erase the words "space" and "time" from our minds and come back at the question. We notice that in life there are things that change and things that stay the same, and often the very same things seem to change and stay the same but in different respects. The baseball is the same baseball, both in the hand of the pitcher and in the glove of the catcher, but it is not wholly the same because some things about it are different, such as its location and its relationship to the things around it. We can talk about things that are constant and changing, or static and dynamic. (In Arabic the relevant terms are qārr and ghayr al-qārr.)
But I do not wish to encumber myself from the beginning with technical language. For now I simply have the "constant" and the "changing". I, too, am constant and changing. I am the same person but I am always becoming this or that, experiencing all sorts of colors and sounds and shapes in addition to my emotions, and yet the constant identity abides. In the statement, "I was sad, then I found my true love, and then I was happy," the then does not split the I into parts. It does not erase the identity.
Such paradoxes of the many in the one, and the one in the many, really form the basis of Ibn al-'Arabī's metaphysics, and make a good point of departure for an analysis of time and non-time. At the highest level, the mystery of the many and the one is the identity between the Ultimate Reality and the many things we usually think of as being real in and of themselves. The ontological status of things in relation to the ultimate reality is a question for metaphysics, but the mystery of the many and one also plays out in cosmology, meaning the study of the world in which the puzzles of constancy and change arise.
At the highest level of Akbarian thought, the manyness of the divine qualities is resolved in the unity of the supreme Self. This is not a unity of "before" and "after", where I might say that all qualities are happening right now; nor is it a unity of "here" and "there", where I might say that all qualities are in one place. Rather it is a unity of being, of identity. The Creator is not another being than the Just or the All-Merciful. They are unified in what they truly are, and mysteriously the world's illusory reality disappears in the face of this essential unity.
Now, Akbarians do not throw away manyness, but put it in its place, and from our point of view in the world the many divine qualities and their relationships to one another are of the greatest significance. The manyness of the qualities is unreal only for the supreme Self, but for us this manyness is as real as we are, so to speak. In fact, we depend on this manyness for whatever illusory reality we possess, because it is by virtue of the divine names and qualities and their relationships that the world comes to be. How, then, does this one in the many, many in the one, play out in the world?
There is no shortage of ideas that Ibn al-'Arabī and his school use to describe how the divine qualities give rise to the world. Some of the most important are emanation (fayd), self-disclosure (tajallī), identification (ta'ayyun). For this talk I want to use the symbolism of light, and the divine name "Light" or al-Nūr. Mystics and philosophers have often started with light, and its symbolism is so powerful because light is both what we see and what we see by. Light is both a means and an end. If we apply the symbolism of light to all knowledge, light is both what we know and how we know. It is, moreover, a symbol that Ibn al-'Arabī and his school often used as a metaphysical basis, the same way they could use the concepts of mercy and existence.
The Quran says, God is the Light of the heavens and the earth (24:35). The heavens and the earth are the realm of the constant and the changing, so let us say that God is the light of the constant and the changing, making God what we know the constant and the changing by. This leaves us to ask what the constant and the changing are. Each and every thing is, ultimately, a manifestation of a name of God. God knows His endless names, and this knowledge is the realm of the immutable identities, the al-a'yan al-thabitah. Each immutable identity is a special way in which God knows God, but God's knowledge of Himself is neither before and after nor here or there. It introduces neither distance nor duration between His names.
But if the identities are essences or forms in the knowledge of God that are separated neither by distances nor durations, how do we get to the situation where these identities, when they are in the world, do get separated by distance and duration? In God's knowledge the identities are immutable, but in the world they are what we are calling constant and changing. They are here and there, and they are before and after. The baseball is here, not over there. Or, the baseball is here now, but it was not here earlier. This does not happen in God's knowledge. The immutable identities are different but not apart. There is an immutable identity for the pitcher and an immutable identity for the catcher, but they exist eternally in God's act of knowing, fused but not confused, to borrow Meister Eckhart's language.
Akbarian cosmogenesis is a two-tiered emanation, or self-disclosure which first gives rise to the immutable identities in God's knowledge, and then externalizes or existentiates them in the world. There is a way in which these two identities, one manifest and the other unmanifest, are two different things, and another way in which they are simply the same thing viewed from two different points of view. When God's light illuminates the immutable identities – which we can reword and say when God as the Light meets with God as the Knower – the result is the world. In a sense the immutable identities are dark, because as independent beings they are nothing. They are only God's knowledge of Himself. The divine light is a gift that illuminates the identities and gives them their own reality. This light allows there to be something "other than God", this phrase "other than God" being Ibn al-'Arabī's definition of the world, because by being illuminated the identities can see each other, and see themselves, and by "see" I mean "know".
Now, in the world this light by which we are illuminated to each other is none other than the very realities of duration and distance. What we give the name "space" is a state of affairs where the forms of things exist in a kind of relationality to each other, separated and yet existing in the same domain and thus connected in a kind of continuum. What we give the name "time" is a state of affairs where forms exist in a different kind of relationality, where even a single given thing is able to be separated from its previous state and yet still be connected to those states by virtue of its being a single thing. Thus its states also exist in a kind of continuum. God's light in static mode is space, and His light in dynamic mode is time. The identities themselves are not space and time, for the identities are pure forms in the knowledge of God, but when God casts His light upon them they enter into the dance of spatial and temporal interaction we call the world. This light enables the realities of sound, color, shape, smell, feeling, number, mass, and energy to connect and manifest the forms. Light is the vessel, both in static and dynamic mode, upon which the identities journey in between the plenary darkness of God's knowledge on the one hand and the uninhabitable darkness of pure nothingness on the other.
This is one possible understanding of the divine saying where God says, "Do not curse time, for I am time." By cursing time, we are in reality cursing the light of God, which is identical with Himself. It is by God giving of Himself, of His light, that our existence as beings going through changing states is even possible. But it then follows that one could also say that God is space. Islamic metaphysics does not have, to my knowledge, a classification of space as it does of time. As I am sure will be widely discussed in this conference, there is a distinction made between sarmad, dahr, and zamān, or eternity, sempiternity, and ordinary time. But if what I am saying about the divine light is true, is it not equally true to say that God is space?
In the bodily world the divine light shines in a certain mode, far short of all the possibilities of divine illumination. The light is relatively dim, and though I see myself and others, I cannot see much, and the wholeness and connectedness of things is largely hidden in a darkness that is yet to be illuminated. The possibilities of this world are basically limited, at least in our ordinary experience, to the usual dimensions of space and time. Akbarian metaphysics teaches that the imaginational world, the world ontologically superior to the world of bodies, is more illuminated. In that world, the rules governing the constant and the changing, or distance and duration, are not the same. Remember that the imaginational world, like the world of bodies, is still a world of extension, which is to say that it is a world of manifested forms – of shapes, colors, duration, changing states. But because it is so luminous, the possibilities for the interaction of the constant and the changing are much greater. The forms in the imaginational world are indeed not limited by bodily space and time, though there is an imaginational space and an imaginational time. Recall the saying that the bodily world in relation to the imaginational world is like a ring tossed into a vast wilderness. Rūmī declares that there is a window between hearts, meaning that we are connected to each other at the level of our souls, both across space and across time. True believers can have dreams foretelling the future, and great saints can meet in spirit if not in body. These wonders do not take place by virtue of bodily existence, but by virtue of the imaginational world, the world of souls.
Not only do the conditions of space and time change from bodily to imaginational existence, but they change from this world to the next, from the dunyā to the ākhirah. This is what Dāwūd al-Qaysarī means when he says that there are some divine names whose governance of the world lasts for a certain duration. That is to say, there is a certain way in which the divine light manifests the forms in our ordinary earthly life, but at the end of the world the cycle of that kind of light, of that particular divine name, will come to a close. The hereafter will then be governed by another divine name, another kind of divine light. That which is impossible here will be possible there because the divine light will illuminate ever more possibilities for the interplay of forms and identities. Space itself will be greater and more infinite, time itself will be infused with greater barakah and potential for realizing the self-disclosures of God.
Thus far I have been discussing the ontological status of time together with space, because I think the two are inseparable insofar as they are two modes of the divine light as far as worldly existence is concerned. But what does the reality of time mean for the spiritual journey of the soul?
If we take Ibn al-'Arabī's metaphysics and cosmology to their logical conclusion, I believe we can say the following. God created us as a freely given gift, simply so that we who were not could be, that we who were nothing could be living beings. But at the same time God experiences all of our pains and our joys, our stupidity and our wisdom, our fear and our courage with us in a mysterious way. Recall the hadīth where God says, "I was sick, and you did not visit Me," (Muslim 4661) and the Quranic verse "Those who hurt God and His Messenger …" (33:57). Yet for God there is no pain, stupidity, or fear, because God is not confined to the moment of suffering. He knows the whole life. God does not move down the line with us as we do, although He lives what we live. God could never suffer as we suffer because for God there is no despair, no hopelessness. Hopelessness is the most human of sufferings.
For God, the pain is like the pain of separation we feel at the very moment we are running to meet our beloved. We are in fact separated, and the effect of running and the distance between us is a kind of suffering, but that suffering is totally redeemed by the hope we have, the certitude, that we have in the meeting with our beloved. The pain that God experiences with us is like the pain we experience while running to our beloved. It is not really a pain at all; it is a part of the fullness of the moment. God sees in our life, when we cannot, the abundance and perfection of our destiny in a way so perfectly complete that the so-called suffering is ever blessed and redeemed in the final reunion. We are not God, though, and so for us the experience of pain is not the same, but it is what it must be for a being God created for joy. When we become more like God, we suffer more in the way God "suffers", so to speak. We gradually experience and taste how death is just a flavor of life.
In us, God is always running to the beloved, He lives the separation in the total light of (re)union, death in the light of life, pain in the light of total bliss. We may think that we are just stamping our feet, out of breath, running to a horizon that never seems to come closer, but we are growing still.
To turn a nothing into a something like God is going to have to hurt sometimes, ripping open nothingness and pulling out a god-like being strand by strand, sinew by sinew, love by love, pain by pain, stupidity by stupidity … into bliss, wisdom, wholeness, and ever greater life.
Think of a pebble in the shoe of the running lover. If that lover had placed all his hope in a perfect shoe, a perfect foot to go in that perfect shoe with a perfect sock, all to create a perfect fit. If he longed for it and made it his great hope, a pebble in his shoe while he was running would crush him, reduce him to anger, despair, agony, humiliation.
But what does a true lover care about a pebble in his shoe? Does he even feel it? Would he care? Perhaps it would make for an even fonder memory of the reunion.
The Quran promises that "… in Paradise the believers shall neither fear nor grieve" (2:62), meaning that the light of God will so illuminate us that we shall see the beauty of all things past and of what may come. It is in the darkness and opacity of the past, the inability to grasp the greater harmony of what happens to us, that causes the pain of grief. In grief, we suffer from the past. In fear, we suffer from the future. When God's light shows us the way, we suffer from neither. The Quran does not deny the passage of time in Paradise, only the difficulties we experience on account of it in this world. Our memory is illuminated and causes us no more trouble, and our imagination, that faculty capable of reaching out to the future, can conceive of no cause for despair or hopelessness. The ignorance built into the darkness of the world simply cannot exist in the full light of God in Paradise. It is thus that the soul transcends time, not by leaving it but by conquering it.
Our destiny in this world is both static and dynamic, which is to say that we are a harmony of parts and of experiences, of aspects and states. We can understand easily that beauty in the spatial sense is the presence of unity in multiplicity, which is to say, of harmony in all its forms. Music is the classic example of dynamic harmony, of a harmony that not only exists statically in a chord for example, but also dynamically, in a progression of counterpoint and in the movements of a melody.
If the soul can conquer time and live in it in Paradise, what about here in this world? What enables us to wake up to the harmony of our destiny in this world and the next? Surely we must acknowledge that an awakening is called for, because we do grieve and fear, groping about in the dark while falling prey to unhappiness and despair. How can we become like God and experience reunion in separation? The Sufis indeed speak of taking on the divine qualities (al-ittisāf bi-sifātillāh), and this is done through the remembrance of God, the dhikr, in all its forms. It is through the dhikr that the light of God shines brighter and brighter upon the soul, transforming and purifying it. A Sufi shaykh has said that when the traveler looks back upon his life, he will see that dhikr as a kind of golden chain passing through all its states and experiences. This means that through the remembrance, practiced faithfully, the Sufi overcomes the vicissitudes of time.
And this brings us finally to the dimension of non-time, which from man's point of view, both in the spiritual life and in the hereafter, is the spirit, or the heart, or the intellect. The heart or spirit or intellect is the point in man where the divine light resides and can shine down into the soul. It is the mysterious divine spark, both created and uncreated, or as some would say, neither. The spiritual life is the wedding of the soul to the spirit, not the elimination of the soul. Remember that by virtue of being made in the image of God we all possess an intrinsic dimension of light ourselves. The illumination we receive is truly just an aspect of our own nature, as Ibn al-'Arabī says so clearly in the Fusūs. In the spiritual life, in the remembrance of God, the spirit or heart acts upon the soul, illuminating it, transforming it, untying its knots, turning it clear where it was once opaque. From the point of view of time, progress is made in tying together our temporal selves with our non-temporal selves so that the former can be transfigured by the latter. When the non-time or eternity of the spirit enters fully into the soul, the Sufi becomes ibn al-waqt, newly born in each moment. Wa Allāhu a'lam.
Tesla continued to experiment with Ether-Akasha, and very soon, he developed a new generation of devices and equipment, but we need to make the story shorter. He discovered that he could imbibe the Ether-Akasha from the surrounding space, and to use it for different very useful works. One of the very crucial discovery was the fact that streams of Ether-Akasha, when hitting the metal object, will induce huge voltages within the lattice of the metallic structure. Of course, this is going on, on micro-level only, and it is harmless for humans. Therefore, due to such enormously high voltages, electrons will be expelled and ejected into the surrounding area, in the air actually, where they will react with atoms of oxygen, and negatively charged ions will be produced. In fact, just in one stroke, two electrons will join to the atom of oxygen, which already has six electrons in the outer shell, and now there will be eight of them. This is one very revolutionary cognition actually, because this is exactly, the principle used along with ancient pyramids. Please, it is extremely important to notice that the top of every pyramid was covered with gold; that was the so-called golden capstone. It was having exactly the same function, to radiate an enormous amount of negative ions all around, after the streams of Ether-Akasha we are surrounded with, strike into them. This principle was used extensively in Marrakesh as well along with Kutubiah. In fact, this principle becomes the main postulate of the sthapatyaveda and the vastu construction science. Indeed, this is the main purpose of the sthapatyaveda; to produce huge amount of negative ions, which will keep the house itself and the complete vastu, the entire plot, under the protection from the influence of positive ions, very bad and devastating for human health, and very devolving when we consider the level of consciousness. The story of negative ions is very important for this essay, it is not so simple, it asks for more explanations, and it will be addressed separately in an additional chapter.
28 Tesla continued to experiment with Ether-Akasha, and very soon, he developed a new generation of devices and equipment, but we need to make the story shorter. He discovered that he could imbibe the Ether-Akasha from the surrounding space, and to use it for different very useful works. One of the very crucial discovery was the fact that streams of Ether-Akasha, when hitting the metal object, will induce huge voltages within the lattice of the metallic structure. Of course, this is going on, on micro-level only, and it is harmless for humans. Therefore, due to such enormously high voltages, electrons will be expelled and ejected into the surrounding area, in the air actually, where they will react with atoms of oxygen, and negatively charged ions will be produced. In fact, just in one stroke, two electrons will join to the atom of oxygen, which already has six electrons in the outer shell, and now there will be eight of them. This is one very revolutionary cognition actually, because this is exactly, the principle used along with ancient pyramids. Please, it is extremely important to notice that the top of every pyramid was covered with gold; that was the so-called golden capstone. It was having exactly the same function, to radiate an enormous amount of negative ions all around, after the streams of Ether-Akasha we are surrounded with, strike into them. This principle was used extensively in Vedic India as well along with temples and private houses. In fact, this principle becomes the main postulate of the sthapatyaveda and the vastu construction science. Indeed, this is the main purpose of the sthapatyaveda; to produce huge amount of negative ions, which will keep the house itself and the complete vastu, the entire plot, under the protection from the influence of positive ions, very bad and devastating for human health, and very devolving when we consider the level of consciousness. The story of negative ions is very important for this essay, it is not so simple, it asks for more explanations, and it will be addressed separately in an additional chapter.
For example, just there in New York, Tesla was raising balloons filled with helium or similar gas easier than air, high in the sky. The balloon itself would have been wrapped with the foil made of aluminum. That was the active metallic material, and the very important element Tesla needed for his devices. It served as an input terminal to his much complex device actually. Tesla was using this device for taping the radiant energy, the Ether-Akasha, from the space around. It is all very complex actually, so I do not want to go deeper into this topic. Just to say that the device could have supplied the energy for heaters to heat homes, for light bulbs, and for electric motors that should have been modified a little bit for that purpose. All that Tesla had achieved already there along with his labs in New York or around.
This is the moment when Tesla cognized the unbounded potential of this Ether-Akasha system he just has developed. This is the moment when he learned how much more advanced this system is comparing to even his newly developed AC polyphase system. This is the moment when he abandoned all further researches on the alternating current and polyphase system. Hence, in some stage, he started the research on the high-frequency polyphase system, but that was also far behind the Ether-Akasha system he just established, and which offered wireless transmission. Therefore, unnecessary expenses for the expensive distributing system is not needed anymore. He did set up the ideal system, which could have been the basis of the Age of Enlightenment actually. Indeed, that was the technology of the Age of Enlightenment.
However, for his system to be complete, he still needed something more to do. His system was designed and tested in New York and the surrounding fields and lawns only. The thing is that he needed to perform an additional set of experiments and an entirely new series of checking and testing. He needed something bigger, something on an industrial scale. New York was not an appropriate terrain for this purpose anymore. After all, officials and authorities would not have allowed such “very hazardous” experiments. He did find a new terrain for his further step, and that was the Colorado Springs.
Project Colorado Springs
… was supposed to be the final testing for something even bigger, for construction of a series of pyramid-like structures, with the same basic function. Actually, each unit would have had many functions. It would be the relay in the network of the same structures, for wireless energy transmission, but at the same time, it would be the source for billions and billions of negative ions to be released in the environment so that local people would be elevated higher in consciousness. Tesla made possible that communication system would be installed along with his relay system. He predicted and prepared the radio communication through his system, but TV as well. He realized that pictures could easily be sent on distances as well. All was supposed to be much better than we have even today because Ether-Akasha is the media with inexhaustible options. Simply, his system had marvelous features, and Humanity was just one-step to the Age of Enlightenment.
For Tesla, Colorado Springs was a very successful project. It did cost a lot, this is true, but it was very important to set up all the parameters of his system. He chose Colorado Springs, because it is in the mountains, very high in altitude. He had used the plateau that was about 2000 meters above the sea level, and he achieved marvelous results during 1899, and 1900.
After that project in Colorado Springs, Tesla was ready for the new and final step, for the construction of the broadcasting tower for his wireless transmitting energy system. That was chosen to be on Long Island, near New York, and especially, near to the water. According to the previous owner of the land, it got the name …
The Wardenclyffe Project
… Indeed, Tesla needed to be close to the water just as ancient pyramids have been once upon a time. He needed to establish a very good grounding system for his broadcasting tower, and for that, he needed a terrain with plenty of underground caverns filled with water, the so-called aquafers. Just like with the real pyramids indeed. Without a good grounding system, the system would not have worked at all
Tesla started with the construction of the broadcasting tower in 1901, right after his very successful Colorado Springs Project. This is where we are coming to a very critical moment. As it seems, when bankers and financiers realized that he is doing something that will activate free use of energy, well, they shut down all his projects immediately. All of sudden Tesla became … persona non-grata. All contracts deals for donations, and sponsoring were broken. This is where the very hard time for Tesla began. Despite everything, as it seems, he finished his broadcasting tower; it was operational for some time, but never fully. Never according to all Tesla’s plans. Nevertheless, Tesla was doing some further experiments, very probably all until 1917, when the complete tower was deconstructed and demolished. Due to war perils, they made an official statement for doing so.
ust to finish this story of Nikola Tesla and Ether-Akasha, which is shortened and minimized maximally, because several encyclopedic volumes would not be enough to deliver all that Tesla did on this topic. Perhaps there will be a good opportunity to focus more on Nikola Tesla because he definitely deserves our full attention. Therefore, maybe even the complete essay of mine will be devoted to Tesla very soon. However, for the moment, I will just be free to expose a few references. There is the beautiful article exposed in Atlantis Rising, January-February edition of 2007, (#61), by Jeane Manning …
Current Wars and our lost “true electric age”
… Another beautiful article from the same magazine, Atlantis Rising, from May-June edition 2012, (#93), by Phillip Coppens, under the title …
The threat to Tesla’s Legacy
t another article from Atlantis Rising, September-October edition of 2010, (#83) …
Nikola Tesla & the God Particle
… by Marc J. Seifer Ph.D. All articles are available through the Atlantis Rising Library, or through some other free services on the web. Today, the person who comprehended the highest knowledge on Tesla’s work is most probably …
Goran Marjanovic
BScE
… from the University of Nis, Serbia. Here there is one recent work of him exposed on the … Academia.edu … www.academia.edu/38109658/Nikola_Teslas_Ether_Technologie... Once again, just to summarize, Nikola Tesla did a great job in deciphering the phenomenon of electricity to the very core. Now we know that any electric or electromagnetic activity is closely connected with, and related to the Ether-Akasha. Nevertheless, why, and how it happened that we do not know about? Why don’t we teach that in the schools? How is it possible that there is no trace or clue to connect the two? However, maybe there are. Maybe we are learning about but under another name!? To document this, I will narrate the story of …
electromotive force
… and my first personal contact with it. Electromotive force is a term defined in electro science to explain why electrons, under certain conditions, are moving around within the crystalline lattice of any metallic structure. This is the very foundation of the science of electricity. I remember the days when I was a young student in a technical school in Zagreb, the school that carries the name of Nikola Tesla by the way, and the school that is devoted to mastering the electronic and electro-technic science and practical skills. This is the kind of school where the knowledge about electric and magnetic phenomena is in the main focus, and this subject is primary in the curriculum. I remember very well the first contact with the term of …
electromotive force
…
emf
… All theories in learning the basic principles in electro science will start with electromotive force actually. It is explaining why electrons are moving around, and why they are doing this and this, and not doing certain other things. Whosoever was learning something about electricity must have passed through this phase. Therefore, they will explain that electrons are moving due to the difference of potentials, what is generating a certain voltage, and what is basically true. However, behind the voltage, they say, there is the electromotive force actually. I also remember very well curiosity of all of us when hearing this story. We wanted to know more about electromotive force itself. Some colleges of mine that were always ready for discussions and polemics of any kind, they immediately raised many questions about
emf
. However, even though we had a brilliant professor who was the legend of the school actually, we could not get any profound answer to what
emf
really is. In fact, this is not the matter of professor, because he also learned it from his professors in the same dogmatic form. This is a very important moment indeed. The basic idea why electrons are moving around is turned into a dogmatic explanation so that in fact nobody knows why they are doing so. Such kind of explanation we call exactly this way …
the dogma
. Well, today, if you ask any engineer of electronic what electromotive force is, well be ready for some very funny answers and explanations. Fine, even by this dogmatic explanation, the field of electronic and the science about electricity has been booming, providing us with very sophisticated equipment and devices. Comparing to life in the 19
th
century and before, our achievements are grandiose. However, is this our maximum? Is this our climax? Are we at the pinnacle of our achievements when electric technology is in the question? Nikola Tesla discovered that the use of Ether-Akasha offers much, much more. Interestingly, we get much more power when we separate gross level electrons, and when we get pure streams of Ether-Akasha. However, this is not all. Such media already is all around us. We already are immersed in the media called Ether-Akasha, just because this is the basic tissue of the Universe itself and of the entire Creation actually. This energy is all around us, and it is free to use. It can even be used wirelessly. All that we need to do is to connect with; we just need to plug in.
Throughout this essay, and throughout some other essays of mine, the term …
negative ions
… was already used on many occasions. However, I think now is the time to say something more about negative ions, and their counterparts …
positive ions
. In general, every atom that loses or receives electrons in the outer shell, that atom becomes an ion. Usually, atoms try to stay electrically neutral, so that the electrically positive charge of protons in the core is equal to the charge of electrically negatively charged electrons in the shell. In fact, in electrical terms, the true counterpart of electrons in the shell, are positrons within the core of the atom. However, this is a very long story. If an atom loses an electron or electrons, it became a positive ion, because its charge has changed in favor of protons in the core of the atom, which carries the positive electric charge. For such an atom, we say that it is positively charged ion. If the atom receives electrons in the outer shell, then it becomes a negative ion because it is negatively charged. The electrons in the shell outnumber the protons in the core of the atom, the equilibrium among charges is lost, and the atom is not electrically neutral anymore, it has a negative charge. It becomes a negative ion. However, our physiology does not react equally to such positive and negative charged ions. It is proved that positive ions are influencing our body in a very bad way. When they enter the body, we call them free radicals, and they will cause the oxidation process. Due to that, they will speed up the aging process, and they will promote the growth of bad bacteria and bad microorganisms, what in the final stage can generate many diseases and health problems. Therefore, scientifically and medically it is proved that positive ions have negative effects on humans, on the level of the physiology, behavior, and wellbeing. Opposite to that, it is observed that negative ions have an extremely beneficial influence on a human body, clearness of the mind, the process of thinking, and can even elevate human consciousness to the higher level. This is to say that we want to increase the number of negative ions in the environment we live in. In addition, we want to increase the number of negative ions within our physiology as well. At the same time, we want to decrease the number of positive ions around and within our body, because, their influence is harmful. We have some natural phenomena that are known throughout history, but only recently have been scientifically validated. When winds blow over dry sandy desert, it will produce and carry with it many positive ions, which will have very bad effects on local people. Usually, it happens with the south wind. From the website …
www.econesthomes.com/natural-building-resources/articles/...
…
cog·ni·tive [kog-ni-tiv]
–adjective
1.of or pertaining to cognition.
2.of or pertaining to the mental processes of perception, memory, judgment, and reasoning, as contrasted with emotional and volitional processes.
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