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Pronghorn can maintain speeds of 30 to 40 miles per hour for long distances.                Jack Woody/FWS

Pronghorn are truly American natives, found only in North America where they have roamed the plains and deserts for at least one million years. They are the only members of the family Antilocapra americana, which means "American goat-antelope," but they are not goats nor antelope. Their pronged horns and their fleetness of foot set them apart from other deer-like mammals.

The pronghorn is the only animal in the world with pronged horns and the only animal that sheds its horns. The pronged horns are made up of two parts, a permanent bony core and a black outer sheath covering composed of a stiff, hair-like substance that is shed annually in the fall to grow back by the summer. (Antlers by comparison are composed entirely of bone and are entirely shed each year.) Although both male and female pronghorn have horns, only the male’s horns are pronged.

Mature male pronghorn, or bucks, weigh between 85 and 130 pounds and mature females, called does, weigh between 75 and 105 pounds. The coloration of the pronghorn varies from light tan to a rich brown with white patches under the stomach and on the rump, with thick manes of dark brown or black hair. Bucks have black patches below their eyes and a black mask that begins at the nose and extends backward.

Pronghorn can see preditors up to 4 miles distant                                    Evan Hirsche	Pronghorn thrive in a variety of habitats.                                      Claire Dobert/FWS

The pronghorn is the fastest North American mammal (second only on earth to the cheetah) and can reach speeds of 60 miles per hour. The pronghorn can cover the ground in strides of 14 to 24 feet and can maintain speeds of 30 to 40 miles per hour for long distances. The pronghorn’s body is built for speed with relatively large lungs, windpipe and heart, allowing them to consume three times the oxygen of a similarly sized animal. Pronghorn run with their mouths open, allowing them to take in even more air. Their padded hooves cushion the shock from running hard over the ground.

Bucks shed their pronged horns every year in the fall.                                        Harvey Doerksen/FWS

The pronghorn has exceptional vision and can detect a predator from three to four miles away. They also have excellent hearing and sense of smell. The pronghorn’s best defense from threats such as coyotes, bobcats, mountain lions or golden eagles is to remain vigilant and to run quickly. The pronghorn is an inquisitive animal but will run from danger, with the does leading the herd and a buck bringing up the rear. The white hairs on the antelope's rump can be held erect, making the antelope appear as a white flash in the bright sunlight and sending a warning signal to other pronghorn.

 

Pronghorn are most active during the mornings and the evening.                 Curtis Carley/FWS

Breeding season begins in late July or early August when the horns on the males have reached their maximum length, usually between 12 to 20 inches. Bucks over three years old become extremely territorial and fight aggressively to defend their territory and their harem of 2 to 4 does. After shedding the outer casings of their horns in the fall, bucks and does tend to travel in large herds during the winter. In the spring, pregnant does will isolate themselves from the herd to give birth. Fawns are born completely scentless and lie motionless for hours, giving them protection from predators in the crucial first few hours of life.

Pronghorn are opportunistic foragers and can consume over 150 different types of grasses, forbs and browse plants, allowing them to occupy a variety of habitat types. Chiefly diurnal, pronghorn antelope are most active in mornings and evenings and are seasonal nomads, depending on the quality and quantity of their open grass habitats.

Pronghorn tend to live in large herds during the winter.                                  H. Hoops/FWS

An estimated forty million or more pronghorn once roamed the American West. But like the once plentiful bison, they were nearly hunted to extinction. By the early 1900s only ten to twenty thousand remained. After decades of recovery efforts, there are now estimated to be one million pronghorn roaming the western prairies and deserts of North America.