[Range]  [Habitat]  [Social Organization]  [Threats]

Although sometimes called antelope, pronghorn are not closely related to the animals of African plains. In fact they are so different from other hoofed animals that they are the only members of the family Antelocapridae. Their head ornaments set them apart from deer and elk whose branched, solid antlers are shed each year, and from goats and cattle whose hollow horns are made from hair and are not shed. Pronghorn have branched, hollow, hairlike horns that are shed annually. They are the only animal with this combination.

True Americans, pronghorn are found only on the plains and grasslands of North America. Like bison, seemingly endless numbers once covered the west, stretching from Saskatchewan to just north of Mexico City. And like bison, they nearly became extinct. Populations declined from an estimated 30-60 million in the early 1800s to less than 15,000 by 1915. A moratorium on hunting lasting until the 1940s and a federal tax on firearms and sporting goods funding conservation efforts are credited with stopping the decline. Today there are almost 1 million pronghorn. Five subspecies are recognized:  American/Common (found in most of range, Canada, and northern Arizona); Mexican/Chihuahuan (found in New Mexico, Texas, formerly southeastern Arizona); Oregon (found in southeastern Oregon); Peninsular (100-250 animals, found in Baja, Mexico); and Sonoran (Endangered, 500 animals found at Cabeza Prieta National Wildlife Refuge and Sonora, Mexico).

All pronghorn in southeast Arizona are reintroduced populations. The herd at Buenos Aires National Wildlife Refuge was transplanted from Texas in 1987 with the aid of state game and fish departments. After initial heavy losses, the herd has stabilized at around 60 animals.

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Habitat

Most pronghorn are found on grasslands receiving between 10-15" of rainfall, between 4,000' and 6,000' elevation. Pronghorn need open, flat valleys to make use of their most famous attributes--speed and eyesight. Vegetation must not exceed 30" so approaching predators are visible. With eyes almost as large as an elephant's on a body the size of a goat, pronghorn are clearly designed for watchfulness. They nap throughout the day, waking to take a look now and then. Once alerted, they can outrun any predator fairly easily. The herd travels as one, not leaving a single animal open to attack. They keep the pace up for miles, their speed and endurance evolving from the pressure of their traditional enemy, the wolf.

Slower solitary hunters, coyote pose a threat only in the first few weeks when a fawn's best defense is invisibility. But as many as 50 percent of a year's fawns may be lost. Does leave deer-colored newborns hidden in the grass, returning to nurse for 30 seconds every 5 hours. What appears to be abandonment actually increases their chances of not being detected.

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During the winter, herds come together and travel in harmony. But come spring, bucks start defending territory and amassing a harem of 2-15 does. Does are attracted to bucks that can provide good feeding grounds for their fawns born from late April-June. This system also provides protection from insistent bachelor bucks. A buck's territory may be 1 square mile. He spends most of his energy defending this territory all summer. He breeds over a few short weeks in late summer, then drops the sheath from his horns. Hormone surges and warring over, herds come together again for the winter.


Threats

Fencing (pronghorn don't jump), loss of habitat (development and conversion of grasslands), coyote (when fawns), and vehicle collisions.

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Last Updated April 15, 2002

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