Scott Hanko
Pronghorn (Female)
The Pronghorn (Antilocapra americana) is a species of artiodactyl mammal endemic to interior western and central North America. Though not an antelope, it is often known colloquially in North America as the Prong Buck, Pronghorn Antelope, or simply Antelope, as it closely resembles the true antelopes of the Old World and one theory is that it fills a similar ecological niche due to convergent evolution. It is the only surviving member of the family Antilocapridae. During the Pleistocene period, 12 antilocaprid species existed in North America. About 5 existed when humans entered North America 13,000 years ago; all but A. americana are now extinct.
Adult males are 1.3–1.5 m (4 1/4–5 ft) long from nose to tail and stand 81–104 cm (2 5/8–3 3/8 ft) high at the shoulder, and weigh 36–70 kg. The females are the same heights as males but weigh 41–50 kg. The feet have just two hooves, with no dewclaws. The body temperature is 38.0°C.
Each "horn" of the Pronghorn is composed of a slender, laterally flattened blade of bone that grows from the frontal bones of the skull, forming a permanent core. As in the Giraffidae, skin covers the bony cores, but in the Pronghorn it develops into a keratinous sheath which is shed and regrown on an annual basis. Unlike the horns of the family Bovidae, the horn sheaths of the Pronghorn are branched, each sheath possessing a forward-pointing tine (hence the name Pronghorn). The horns of males are well developed.
The orbits (eye sockets) are prominent and sit high on the skull; there is never an antorbital pit.
Males have a prominent pair of horns on the top of the head, which are made up of an outer sheath of hairlike substance that grows around a bony core; the outer sheath is shed annually. Males have a horn sheath about 12.5–43 cm (mean 25 cm) long with a prong. Females have smaller horns, ranging from 2.5–15 cm (average 12 cm), and sometimes barely visible; they are straight and very rarely pronged. Males are further differentiated from females in that males will have a small patch of black hair at the angle of the mandible. Pronghorns have a distinct, musky odor. Males mark territory with a scent gland located on the sides of the head.[5] They also have very large eyes, with a 320 degree field of vision. Unlike deer, Pronghorns possess a gallbladder.
It can run exceptionally fast, being built for maximum predator evasion through running, and is generally accepted to be the fastest land mammal in the New World.[6] The top speed is very hard to measure accurately and varies between individuals; it is variously cited as up to 70 km/h, 72 km/h,[5] or 86 km/h. It is often cited as the second-fastest land animal, second only to the cheetah. It can, however, sustain high speeds longer than cheetahs. University of Idaho zoologist John Byers has suggested that the Pronghorn evolved its running ability to escape from extinct predators such as the American cheetah, since its speed greatly exceeds that of extant North American predators. It has a very large heart and lungs, and hollow hair. Although built for speed, it is a very poor jumper. Their ranges are often affected by sheep ranchers' fences. However, they can be seen going under fences, sometimes at high speed. For this reason the Arizona Antelope Foundation and others are in the process of removing the bottom barbed wire from the fences, and/or installing a barb-less bottom wire.
The pronghorn has been observed to have at least 13 distinct gaits, including one reaching nearly eight yards per stride.
Pronghorns form mixed-sex herds in the winter. In early spring the herds break up with young males forming bachelor groups, females forming their groups and adult males living a solitary life. There are female bands which share the same summer range and bachelor male bands form between spring and fall. Females form dominance hierarchies with few circular relationships. Dominant females will aggressively displace other females from feeding sites.
Adult male pronghorns employ two different mating strategies during the breeding season. A pronghorn male will defend a fixed territory that females may enter or it might defend a harem of females. A pronghorn may change mating strategies depending on environmental or demographic conditions. In areas that have high precipitation, adult male pronghorn tend to be territorial and maintain their territories with scent marking, vocalizing and challenging intruders. In these systems, territorial males have access to better resources than bachelor males. Females also employ different mating strategies. "Sampling" females visit several males, remain with each male a short time, and switch between males at an increased rate as estrus approaches. "Inciting" females behave as samplers until estrus; then they move away from the male, inciting fights and other aggressive competition. Inciting females watch the competition, and they always mate immediately with the winning male. "Quiet" females move to an isolated, peripheral location occupied by a single male, and remain with that male throughout estrus.
When courting an estrous female, a male pronghorn will approach her while softly vocalizing[18] and waving his head side to side, displaying his cheek patches. A receptive female will remain motionless and sniff his scent gland and then allow the male to mount her. Pronghorns have a gestation period of 235 days, longer than is typical for North American ungulates. They breed in mid-September, and the doe carries her fawn until late May. This is around six weeks longer than the white-tailed deer. Newborn Pronghorns weigh 2--4 kg, most commonly 3 kg. In their first 21-26 days, a fawn spends time hiding in vegetation. Fawns interact with their mothers for only 20-25 minutes a day and this continues even when the fawn joins a nursery. The females nurse, groom, distract predators and lead their young to food and water. Males are weaned 2-3 weeks earlier than females. Sexual maturity is reached at 15 to 16 months, though males rarely breed until 3 years old. The longevity is typically up to 10 years, rarely 15 years.
Queens Zoo Flushing New York
Pronghorn (Female)
The Pronghorn (Antilocapra americana) is a species of artiodactyl mammal endemic to interior western and central North America. Though not an antelope, it is often known colloquially in North America as the Prong Buck, Pronghorn Antelope, or simply Antelope, as it closely resembles the true antelopes of the Old World and one theory is that it fills a similar ecological niche due to convergent evolution. It is the only surviving member of the family Antilocapridae. During the Pleistocene period, 12 antilocaprid species existed in North America. About 5 existed when humans entered North America 13,000 years ago; all but A. americana are now extinct.
Adult males are 1.3–1.5 m (4 1/4–5 ft) long from nose to tail and stand 81–104 cm (2 5/8–3 3/8 ft) high at the shoulder, and weigh 36–70 kg. The females are the same heights as males but weigh 41–50 kg. The feet have just two hooves, with no dewclaws. The body temperature is 38.0°C.
Each "horn" of the Pronghorn is composed of a slender, laterally flattened blade of bone that grows from the frontal bones of the skull, forming a permanent core. As in the Giraffidae, skin covers the bony cores, but in the Pronghorn it develops into a keratinous sheath which is shed and regrown on an annual basis. Unlike the horns of the family Bovidae, the horn sheaths of the Pronghorn are branched, each sheath possessing a forward-pointing tine (hence the name Pronghorn). The horns of males are well developed.
The orbits (eye sockets) are prominent and sit high on the skull; there is never an antorbital pit.
Males have a prominent pair of horns on the top of the head, which are made up of an outer sheath of hairlike substance that grows around a bony core; the outer sheath is shed annually. Males have a horn sheath about 12.5–43 cm (mean 25 cm) long with a prong. Females have smaller horns, ranging from 2.5–15 cm (average 12 cm), and sometimes barely visible; they are straight and very rarely pronged. Males are further differentiated from females in that males will have a small patch of black hair at the angle of the mandible. Pronghorns have a distinct, musky odor. Males mark territory with a scent gland located on the sides of the head.[5] They also have very large eyes, with a 320 degree field of vision. Unlike deer, Pronghorns possess a gallbladder.
It can run exceptionally fast, being built for maximum predator evasion through running, and is generally accepted to be the fastest land mammal in the New World.[6] The top speed is very hard to measure accurately and varies between individuals; it is variously cited as up to 70 km/h, 72 km/h,[5] or 86 km/h. It is often cited as the second-fastest land animal, second only to the cheetah. It can, however, sustain high speeds longer than cheetahs. University of Idaho zoologist John Byers has suggested that the Pronghorn evolved its running ability to escape from extinct predators such as the American cheetah, since its speed greatly exceeds that of extant North American predators. It has a very large heart and lungs, and hollow hair. Although built for speed, it is a very poor jumper. Their ranges are often affected by sheep ranchers' fences. However, they can be seen going under fences, sometimes at high speed. For this reason the Arizona Antelope Foundation and others are in the process of removing the bottom barbed wire from the fences, and/or installing a barb-less bottom wire.
The pronghorn has been observed to have at least 13 distinct gaits, including one reaching nearly eight yards per stride.
Pronghorns form mixed-sex herds in the winter. In early spring the herds break up with young males forming bachelor groups, females forming their groups and adult males living a solitary life. There are female bands which share the same summer range and bachelor male bands form between spring and fall. Females form dominance hierarchies with few circular relationships. Dominant females will aggressively displace other females from feeding sites.
Adult male pronghorns employ two different mating strategies during the breeding season. A pronghorn male will defend a fixed territory that females may enter or it might defend a harem of females. A pronghorn may change mating strategies depending on environmental or demographic conditions. In areas that have high precipitation, adult male pronghorn tend to be territorial and maintain their territories with scent marking, vocalizing and challenging intruders. In these systems, territorial males have access to better resources than bachelor males. Females also employ different mating strategies. "Sampling" females visit several males, remain with each male a short time, and switch between males at an increased rate as estrus approaches. "Inciting" females behave as samplers until estrus; then they move away from the male, inciting fights and other aggressive competition. Inciting females watch the competition, and they always mate immediately with the winning male. "Quiet" females move to an isolated, peripheral location occupied by a single male, and remain with that male throughout estrus.
When courting an estrous female, a male pronghorn will approach her while softly vocalizing[18] and waving his head side to side, displaying his cheek patches. A receptive female will remain motionless and sniff his scent gland and then allow the male to mount her. Pronghorns have a gestation period of 235 days, longer than is typical for North American ungulates. They breed in mid-September, and the doe carries her fawn until late May. This is around six weeks longer than the white-tailed deer. Newborn Pronghorns weigh 2--4 kg, most commonly 3 kg. In their first 21-26 days, a fawn spends time hiding in vegetation. Fawns interact with their mothers for only 20-25 minutes a day and this continues even when the fawn joins a nursery. The females nurse, groom, distract predators and lead their young to food and water. Males are weaned 2-3 weeks earlier than females. Sexual maturity is reached at 15 to 16 months, though males rarely breed until 3 years old. The longevity is typically up to 10 years, rarely 15 years.
Queens Zoo Flushing New York