- A-Z Animals
The Pronghorn is the fastest land mammal of North America and the Western Hemisphere. Though not a true antelope, this ungulate is colloquially called in different names like prong buck, pronghorn antelope, cabri (in Native American language), or just antelope. This is because it has some strange resemblance to the old world antelopes. This very common species of artiodactyl mammal evolved alongside the already-extinct North American cheetah and is spread all across America. But this herbivore is the only surviving member of the family Antilocapridae.
Size: From tip of nose to tail tip, both the adult males and the females are of same size: 4 feet 3 inches–4 feet 11 inches by length, and stand 32–41 inches by height (at the shoulder).
Weight: Males weigh 88–143 lb, while the females weigh between 75 and 106 lb.
Fur/hair/coat: They are usually fawn, brownish to copper orange and have distinct white furs across their throats, on their bellies, sides, breasts and rumps.
Feet: Each foot has two hooves without dewclaws.
Eyes: Prominent and large, set high above on the skull with 320° field of vision and sharp eyesight.
Nose: Dark nose with long snout and black nostrils.
Tail: Short like most other ungulates like deer, goats and antelopes.
Horns: Backward-curving, with branched sheaths. The difference between the sheaths of the male and the female is that, the latter has smaller horns that are seldom pronged, and at times hardly visible.
Teeth: Hypsodont set of teeth with dental formula:
The life span of the pronghorns is typically 10 years in the wild, but rarely 15. They can live for up to 11 years in zoos/captivity.
The range of the pronghorns extends south through the land of North America from southeastern Oregon, south of Idaho, southern Saskatchewan and Alberta, Canada, Montana, and western North Dakota, south to Arizona and western Texas.
Presently, pronghorns are confined to fragments of its former range. Only four small populations of pronghorns have remained, with two of them in the south-west of Arizona, while the other two separate populations live in Mexico.
The greatest concentrations of pronghorns are found 3,000 to 8,000 feet above the sea level. The pronghorns dwell in the grasslands, Mediterranean-type shrubby vegetation, the shrub lands and the temperate desert regions. They are most frequently associated with flat terrains with less number of trees and short-grass prairies, steppes.
Pronghorns have four subspecies and have been named according to their habitat regions:
The activity schedule of the pronghorns varies highly and is affected by weather, season, region, or herd dynamics. Pronghorns have a very strong herd instinct. Their herd composition can vary anything between 3 and 1000 individuals. The number, however, varies mostly seasonally. This herding instinct has made it difficult for the predators to prey and feast upon these creatures.
They form their mixed-sex herd around winter springtime that splits before spring with the young males forming their own bachelor group, females making all-female group while the males live a solitary life.
The males are territorial and often defend a group of females or harem. They mark their territory by using a linked sniff-paw-urinate-defecate sequence, as also with secretions from cheek glands. The owner of the territory would initially warn the intruder, after which the latter is driven away by force. However, horn fights are rare, which, at times, even lead to serious stab wounds and resultant deaths. Sometimes, the adult males also form territorial bands containing more than one male.
These creatures are mostly crepuscular, being the most active during dawn and dusk. They sleep frequently; however, the sleeping periods are short. They are good swimmers. They spend most of their time feeding and resting.
The herbivorous pronghorns spend 40 to 60 percent of time feeding. They mainly eat herbs, forbs, cactus, and desert grasses like bunchgrass, bluegrass, ricegrass, squirreltail and bottlebrush. Like many other ungulates and bovine species, they often ruminate (chew the cud, or semi-digested food). During winter, these creatures consume shrubs like shrubs sagebrush, rabbitbrush, bitterbrush, and other plants that are available.
The breeding season of the pronghorn is mid-September. The males reach the age of sexual maturity at age one year, while it’s 16 to 17 months for females. The females use several strategies to direct mating choice. They visit few harem-holding males and stay there for a few days until it returns back for mating to a male they visited within a week of estrus.
The females sometimes use sampling behavior as well until estrus and eventually escape from the male. This incites chasing, aggressive behavior and fights between males, which the female waits and watches and finally ends in mating with the winner. A month prior to the estrus, a female would move to an isolated place belonging to a single male, where it spends time until mating.
During mating, the males approach the females with a high-pitch whining sound. This gives a sexual indication to the female, who would raise its tail up and stand. With this, the male approaches moving its head from side to side with a low sucking sound before it mounts the female.
While mating, the tip of a male’s penis is usually the first part that touches the female. The actual act of copulation is usually short, with a single forceful pelvic thrust.
The gestation period of the pronghorn is 245 to 255 days, after which, the female gives birth to 1 or mostly 2 babies. The juveniles attain their full weight within 4½ years. The newborns, being the most vulnerable to predators, spend their first 3-4 weeks hiding under vegetation. The females nurse their babies about thrice a day, lead them to sources of food and water, guard them against predators, interacting with them for about 20-25 minutes every day. The baby pronghorns depend on their mothers’ milk until they attain the age of weaning at 4 or 5 months.
Local animals like coyotes, cougars, bobcats, wolves are their major predators. It has been reported that the golden eagles prey on both the fawns and the adults.
The pronghorn doesn’t belong to a threatened species. The IUCN 3.1 has categorized them under the ‘LC’ (Least Concern) species list.