American antilocapra

The pronghorn or American antelope (Antilocapra Americana) is a species of artiodactyl mammal of the family Antilocapridae. It is the only current representative of its family, although until the beginning of the Pleistocene it had numerous species. As time went by, they all became extinct for various reasons, leaving the current pronghorn as the only vestige of their presence.

Description

Although they are called American antelopes, they are not true antelopes. They present a marked sexual dimorphism, with the males being older, weighing 45-60 kg, while the females weigh between 35 and 45 kg. It differs from the rest of the hollow-horned ruminants by having deciduous horn cases. Both sexes have curved, backward-facing antlers that they shed every year, like deer, but they never detach from the bony base beneath the horny surface. These horns are larger and branched in males (125 to 450 mm), while females have short and unbranched horns (25 to 150 mm). Both females and males have a crown of hair at the base of the horns. horns and a black mane.

Its body length is 1.30 to 1.50 m, height at the withers is 70 to 80 cm and its tail is 10 cm long while its ears are 15 cm long.

The shape of the body is reminiscent of antelopes, since like them, their backs are higher than their shoulders. Their limbs are thin and long and have no lateral digits. As for the coat, it is fawn or pronghorn on the back, where its name in Spanish comes from, although in winter it darkens slightly. It lightens in the lower parts of the body until it turns white on the face, throat, belly, legs and buttocks. A characteristic element of this species is the presence of a large white spot around the caudal region. It is present in males, females and babies. The fur in this area stands up when the animal senses danger, serving as a warning to other members. of the group. Two white bands stand out on the neck, one at the height of the throat and the other below it. There are bands of dark hair on the nose, forehead, cheeks, back of the neck and back of the tail. The legs have four fingers, although they walk on two.

Distribution and habitat

The pronghorn is native to North America, found from southern Canada, through the western United States, to northern Mexico (Baja California, Sonora, Chihuahua, Coahuila and Hidalgo).

The characteristic habitat of these animals is open spaces, such as grassy plains and semi-deserts.

Natural history

They feed for much of the day on grasses, bushes, mosses and sometimes even cacti. Pronghorns move in large groups, sometimes herds of hundreds of animals, especially in summer. The members of these packs are always females with their young and young males. Adult or old males are usually solitary or live in small groups, although sometimes they can also form herds made up only of male individuals. In autumn, males of reproductive age compete against each other, fighting head to head in order to earn the right to reproduce. Unlike many other ungulates, males do not abandon herds of females and young after the mating season, but rather join them throughout the following winter.

After 230 days of gestation, females give birth to one calf (if it is their first birth) or two in the month of June. These little ones are gray in color and weigh 2 to 4 kg. Immediately after giving birth, the females separate their babies and hide them in the undergrowth, although they remain vigilant in the nearby areas and come regularly to nurse them.

Predators and conservation status

Currently they do not have true predators. They are the fastest mammals in North America, being able to run at 65 km/h for several kilometers, jumping from 3 to almost 6 meters. Their maximum recorded speed is 98 km/h.^{[citation required]}

Due to this, it is rare for them to die as prey to other animals. Wolves, coyotes, lynxes, pumas and golden eagles can kill chicks that are just a few days old, but even this is not common, as small pronghorns can spend hours crouching among the vegetation and without making any movement that could give them away. A few weeks after birth they stop hiding and follow their mother, already being faster than their potential hunters until then.

The possible cause of the speed of the American antelope is that until just 20 millennia ago it did have a predator to really worry about. Felines similar to the cheetah of Asia and Africa, belonging to the extinct genus Miracinonyx, lived in the American grasslands, which probably reached speeds similar to this one (105 km/h in short stretches). Speed and running endurance were developed to outwit them, and when American cheetahs became extinct at the end of the last ice age, pronghorns simply remained as fast as they had been before.

Due to this absence of predators, American antelopes multiplied without problems during the Holocene, and upon the arrival of the first Europeans they formed herds of millions of specimens on the plains of Canada, the United States and Mexico. This changed with the so-called “conquest of the West.” Like bison, pronghorns were brutally slaughtered by settlers throughout the 19th century, dying thousands every year. In 1908, there were fewer than 20,000 copies left worldwide. Before the species declined further, laws were passed to protect it and its habitat, so the population has currently increased to almost 3 million animals, being especially abundant in the protected areas of Wyoming and Colorado. In some areas hunting has been allowed again in order to control excess population. In Mexico it was usually hunted to feed the El Boleo miners, until 1922 when it became a protected species and hunting became illegal.

Subspecies

The following subspecies are recognized:

• American Antilocaping (Ord, 1815)
• Mexican American Antilocapra Merriam, 1901
• Antilocapra American oregona V. Bailey, 1932
• American Peninsula Antilocapra Nelson, 1912
• Antilocapra American sonoriensis Goldman, 1945