Pronghorn | Antilocapra americana

Copyright Darren Choate

Pronghorn

Antilocapra americana

The distinctly American pronghorn is one of the modern conservation movement’s biggest success stories. Though not a true antelope – it is a species of artiodactyl (even-toed, hoofed) mammals, and is the only surviving member of the family Antilocapridae, which dates back 20 million years– it is commonly referred to as antelope or pronghorn antelope. As a member of the superfamily Giraffoidea, the pronghorn’s closest living relatives are the giraffe and okapi. Its scientific name literally means “antelope goat.”

Pronghorn stand 35-41 inches at the shoulder, measure 49-57 inches long, with bucks weighing 90-140 lbs., and does weighing 75-105 lbs. The upper body and outside of the legs are a pale or reddish-tan, while the sides, chest, belly, inner legs, and rump patch are white. Two broad white blazes are found across a tan throat, with the cheeks and lower jaw white. Bucks also have a broad, black band from the eyes down the snout to a black nose and neck patch. They also have a short erectile mane, about 2 1/2-4 1/2 inches long.

Pronghorn also have true horns, not antlers, made from keratin (as are human fingernails.) Mature buck horns measure from 10-20-inches in length, although any over 16-inches are exceptional. The horns are lyre-shaped, curving back and slightly inwards near conical tips, which may be polished an ivory color. Each has one broad, short prong jutting forward about halfway from the base. Doe horns are no more than 3-4 inches long, with no prong. Pronghorn are, in fact, the second-fastest land animal in the world, surpassed only by the cheetah. Pronghorn have been clocked at 70 mph for up to four minutes at a time and can cruise at 30 mph, a speed they can hold for 15 miles or more. They rely primarily on this blazing speed and their extremely acute eyesight as their first line of defense against predation.

The pronghorn’s range extends from Southern Alberta and Saskatchewan south to California, Arizona, New Mexico, and West Texas, and down into northern Mexico. The Missouri River marks a general eastern geographic boundary, with populations extending west into California and southern Oregon. Classic pronghorn habitat is grassland, grassland/brushland mix, and bunch grass-sagebrush areas. In most areas, sagebrush is the most important browse. Grass is used to a lesser extent but is important in spring. Alfalfa is a favored food when available. The amount of water pronghorn need is dependent upon the availability of succulent green vegetation and the season. One California study showed a daily consumption rate of 0.34 quart/day in May and 4.8 quart/day in August. Pronghorn are mostly crepuscular but may be active day or night. Peak feeding time is shortly after sunrise and shortly before sunset.

An estimated 30-40 million pronghorn once roamed North America, a number some scientists believe is more than even the bison, whose historical numbers are legend. The arrival of the European settlers was the pronghorn’s downfall. The settlers hunted both sexes all year long with little or no restraint until the animals were completely wiped out in some areas, or shot so low in others that they were barely hanging on. At the turn of the century, the remnants of the once vast pronghorn herds were found only in small, isolated areas. The lowest documented number I could find comes from the annual report of the American Bison Society in 1910, which pegged the number at about 13,000.

By the 1920s the public was clamoring for action to save both the pronghorn and the other game species that had been hunted literally to death by the settlers. By now no pronghorn hunting was permitted. California closed its pronghorn season in 1883. Nevada, Oregon, Montana, and Oregon had done the same by 1909. The first thorough survey of pronghorn numbers in Canada, the U.S., and Mexico was conducted between 1922-24, published in 1925 by U.S. Bureau of Biological Survey (later renamed U.S. Fish & Wildlife Service) biologist Edward W. Nelson. He pegged their numbers at some 30,400 animals. To further boost pronghorn protection, the Hart Mountain National Antelope Refuge (today called Hart Mountain National Wildlife Refuge) in eastern Oregon was established on Sept. 6, 1935. On December 21, 1936, the Charles Sheldon Antelope Range (later combined with another refuge to form Sheldon National Wildlife Refuge) was established in northern Nevada.

In 1968 — 52 years after Nelson’s report — the results of the next comprehensive pronghorn population survey were presented to the Pronghorn Antelope Workshop in Cheyenne, Wyoming. Based on 1964 data, it showed a population estimate of some 386,300 — an increase of over 1000 percent. In 1976, another survey was conducted, and it showed a population of some 431,600 pronghorn. In 1985, yet another survey was conducted, this time showing a population of some 1,051,500 pronghorn. In spite of the increased human population, energy development, and agriculture in pronghorn country, as well as controlled sport hunting, the animals had more than doubled their numbers in that decade.

I haven’t been able to track down a concrete figure showing current population numbers. However, most people have it pegged at somewhere around 750,000. Numbers — and available hunting permits — fluctuate annually, depending on how the animals survived the winter, and current predation by coyotes, eagles, and other animals who welcome pronghorn meat at their dinner table. And that’s understandable, for when properly cared for, pronghorn meat is some of the most delicious you’ll ever eat.

Fast Facts

  • Unlike deer, pronghorn possess a gallbladder.
  • A pronghorn’s eyes are as big as an elephant’s, giving vision estimated to be comparable to an 8X binocular. They are also set in the skull so as to give the animal a 320 degree field of vision.
  • While pronghorn do not see color as humans do, their eyesight is extremely sensitive to picking up motion, which it sees before determining the shape of the motion maker.
A successful pronghorn antelope harvest.
A successful pronghorn antelope harvest.