chavez59
Population Evaluation
Interest Research
The organism selected for study in Coyote Creek is a ladybug of the Family Coccinellidae. Ladybugs disperse mainly through flying using their wings and are found worldwide. The common American species, known as the seven-spotted ladybug, was native to Europe and was brought to America to control aphid populations. Ladybugs reproduce sexually and will store sperm for a few months before laying eggs that are usually number between one or two dozen. Adaptations of the ladybug are its aposematic coloration that warns predators off and its ability to secrete an oily fluid from its exoskeleton that deters predatory feeding.
Observations
Only a single population was found on the site near the creek area. The nearest breeding members reside on the same plant which occupies a space of around four feet. The distribution is clumped into one single area, although each member of the population is distributed randomly throughout this small space. The location of the ladybugs population is on the only flowering plant in the site which is expected since its food source of aphids is more likely to be found here than on any of the other plants which are mostly aquatic. This population is most likely a sink since the food and available plant life is highly limited for these organisms and does not have a high number of ladybugs residing within the population. Offspring from this small population most likely go to the nearby fields of wildflowers located just west of the creek where there is little human activity. Immigrants might come from this adjacent field and enter the creek system as they search for sources of food, but most likely do not stay as food is not abundant.
Calculations
According to the geometric growth model the estimated five ladybugs capable of reproduction should have a population of around 1200 in a 5 year time period. In 20 years the population should reach over 1 million. The population will most likely not experience this type of growth as resources are severely limited in this area for the particular location and most of the ladybugs will likely die off or migrate to more favorable areas in San Jose.
Literature
The ladybug population is related to a conservation effort and study mentioned in the SimUtext discussing allee effects. Researchers, including F. Courchamp, in 2011 were trying to save the Kakapo, a flightless endangered parrot in New Zealand. With only 131 birds left which are spread over several islands, the researchers were observing and documenting allee effects in the population. This phenomenon occurs when a small population size by itself decreases the population growth rate. The researchers concluded that allee effects are a crucial part of understanding population dynamics. The population of lady bugs is probably experiencing allee effects as the population size is incredibly small and difficultly mating will probably cause the population to disappear. Additionally, work by Lorne Wolfe in 2002 on alien invaders applies to this organism population. All of the ladybugs spotted were seven-spotted ladybugs which are native to Europe. Wolfe studied snowy campions and found that exotic species do better in the new environments because they can take advantage of new environments. In this area, most of the native species have been outcompeted and no native ladybugs were found near the creek. This is due to the idea that foreign introductions often out-compete natives by escaping their enemies back home and exploiting the new resources they find.
Population Evaluation
Interest Research
The organism selected for study in Coyote Creek is a ladybug of the Family Coccinellidae. Ladybugs disperse mainly through flying using their wings and are found worldwide. The common American species, known as the seven-spotted ladybug, was native to Europe and was brought to America to control aphid populations. Ladybugs reproduce sexually and will store sperm for a few months before laying eggs that are usually number between one or two dozen. Adaptations of the ladybug are its aposematic coloration that warns predators off and its ability to secrete an oily fluid from its exoskeleton that deters predatory feeding.
Observations
Only a single population was found on the site near the creek area. The nearest breeding members reside on the same plant which occupies a space of around four feet. The distribution is clumped into one single area, although each member of the population is distributed randomly throughout this small space. The location of the ladybugs population is on the only flowering plant in the site which is expected since its food source of aphids is more likely to be found here than on any of the other plants which are mostly aquatic. This population is most likely a sink since the food and available plant life is highly limited for these organisms and does not have a high number of ladybugs residing within the population. Offspring from this small population most likely go to the nearby fields of wildflowers located just west of the creek where there is little human activity. Immigrants might come from this adjacent field and enter the creek system as they search for sources of food, but most likely do not stay as food is not abundant.
Calculations
According to the geometric growth model the estimated five ladybugs capable of reproduction should have a population of around 1200 in a 5 year time period. In 20 years the population should reach over 1 million. The population will most likely not experience this type of growth as resources are severely limited in this area for the particular location and most of the ladybugs will likely die off or migrate to more favorable areas in San Jose.
Literature
The ladybug population is related to a conservation effort and study mentioned in the SimUtext discussing allee effects. Researchers, including F. Courchamp, in 2011 were trying to save the Kakapo, a flightless endangered parrot in New Zealand. With only 131 birds left which are spread over several islands, the researchers were observing and documenting allee effects in the population. This phenomenon occurs when a small population size by itself decreases the population growth rate. The researchers concluded that allee effects are a crucial part of understanding population dynamics. The population of lady bugs is probably experiencing allee effects as the population size is incredibly small and difficultly mating will probably cause the population to disappear. Additionally, work by Lorne Wolfe in 2002 on alien invaders applies to this organism population. All of the ladybugs spotted were seven-spotted ladybugs which are native to Europe. Wolfe studied snowy campions and found that exotic species do better in the new environments because they can take advantage of new environments. In this area, most of the native species have been outcompeted and no native ladybugs were found near the creek. This is due to the idea that foreign introductions often out-compete natives by escaping their enemies back home and exploiting the new resources they find.