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.
Table of Contents
Pronghorn Scientific Classification
Table Of Content
Table of Contents
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.
Habitat: Where do Pronghorns live
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.
Classification of Species
Pronghorns have four subspecies and have been named according to their habitat regions:
- A. a. americana
- A. a. mexicana
- A. a. oregona
- A. a. peninsularis
- A. a. sonoriensis
Behavior and Lifestyle
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.
Diet: What Do Pronghorns Eat
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.
Mating, Reproduction, Sexual Behavior
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.
Life Cycle of the Baby Pronghorn
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.
- The pronghorn adapted itself both as a sprinter and an endurance runner for the first time when it evolved alongside the already-extinct North American cheetah, which caught prey in a short dash.
- Movement (motion) comes easily for the pronghorn, which is its primary strategy for survival.
- Conspicuously keen senses of vision and hearing make the animal be aware of the impending danger even when miles away.
- The mammal has been built for maximum predator evasion by means of running.
- The extremely gregarious nature of these animals helps them immensely to keep predators away from attacking unnoticed.
- The large windpipe, heart and lungs of the ungulate is such that, it can take in large amounts of air while running.
- The two long, cushioned, pointed toes in the hooves help them as shock absorbers when they run at high speeds.
- Pronghorns have an extremely light bone structure and hollow hair, which again make it even easier for them to carry their body weight while in high motion.
- The small digestive tract of the herbivore is made to use less energy during locomotion.
- They are an animal marked by speed. This itself is an important and effective defense mechanism since the pronghorn lives in open areas, where there is no place to hide from its predators.
- The sharp hooves of the pronghorn also help them in defense, as a weapon to attack, if they feel threatened.
- The scent gland near their tail produces a strong smelling liquid to warn other pronghorns of the nearing danger.
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.
- The branched sheaths in the horns of the pronghorns possess forward-pointing tines from which it has got its name.
- The pronghorn is the second fastest land mammal in the world, after the cheetah.
- They are able to run at speeds of about 60 miles per hour. Though not as fast as the cheetahs, but they can maintain a continuous fast speed for a much longer period of time than the cheetahs. This means, when a cheetah is out of breath and energy, the pronghorn is still running.
- Because they are so elusive, the subspecies Sonoran Pronghorns are also known as “prairie ghosts”.
- The pronghorns are the only mammals that have forked horns that shed every year.
- The white hairs on the pronghorn’s rumps are glossier and longer than the hairs on the other parts of its body. The rump hairs stand up to flash warning to the other herd members about any forthcoming predator.
- The body temperature of the pronghorn is 100°F.
- Unlike the deer, the pronghorns possess a gallbladder just like sheep and goats do.
- These animals have a distinct musky odor. The male pronghorns mark their territory with a preorbital scent gland located on the sides of the head.
- The pronghorn can run 35 mph for 4 miles, 42 mph for 1 mile, and 55 mph for 0.5 mile.
- If their adaptability is studied closely it is evident that the Pronghorns are built for speed, not for jumping.
- Pronghorns are more of a crawling-under type than the jumping-over If a pronghorn encounters a fence, it will usually crawl under it. They would rarely jump over one.
- It has been studied that, pronghorns have at least 13 distinct gaits with one of them reaching almost 7.3 m (8.0 yd) per stride.
- In order to avoid being detected by predators, the young ones have almost no odor.
- The female pronghorns might at times be harassed by bachelor males especially due to the male’s increasing aggression of the approaching estrus. At this time, the females would often take refuge with a territorial male that eventually chases the bachelor off.