Minnesota’s bone-chilling winters and hot summers are nothing for the pronghorn. This animal’s outer hair, which can be raised or lowered to ventilate the body or seal it off from the cold, allows it to tolerate temperatures from well below zero degrees to 100 F.

What They Eat
Diet consists mainly of forbs (non-woody flowering plants) and grasses and brush. Pronghorn are one of the few large herbivores that can eat sagebrush.

Where They Live
Pronghorns roam the wide-open spaces of the American West where annual precipitation is 8–15 inches per year and a variety of grasses, forbs, and shrubs abound. They share their habitat with a number of other animals, including coyotes, rabbits, prairie dogs, and snakes. They can find sufficient food not only in short-grass and tall-grass prairies but also in shrubby steppe habitat and semidesert terrain. Pronghorns avoid areas with trees.

What They Do
In summer they travel in small groups. In winter they may gather in herds of 1,000 animals.

How They’re Doing
Close to extinction in the 1920s, pronghorn have recovered to the point where there are about 700,000. Fifteen states have pronghorn hunting seasons.

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Pronghorn

Pronghorn

• Pronghorns are thought to have evolved during the Pleistocene (1.8 million to 10,000 years ago) with a cheetah like cat, which explains their great speed.
• The pronghorn is the only animal in the world whose horns are branched or pronged. It also is the only animal that sheds its horn sheath. A new horn grows on the bony core, which is not shed.
• Pronghorns are very curious animals. Settlers often waved a red flag to lure them into rifle range.
• The pronghorn is found only in North America.

Care at the Zoo

Young pronghorns, called fawns, receive special care at the Zoo for a special reason. A pronghorn’s instinct is to blindly flee when startled. This works well when it is trying to protect itself from predators in the vast grasslands of the American West. In a zoo, however, it can lead to injury if the animal runs into barriers or fences. 

To help fawns get used to people and avoid injury, we remove fawns from the herd when they are one day old and house them in individual rearing facilities. Keepers feed each fawn with a bottle, holding it on their lap and placing a hand or arm over the animal’s forehead to simulate touching mom’s abdomen as it nurses.  At 2–3 weeks of age the fawns can be housed together. When they are down to one feeding a day, fawns are reintroduced to the adult herd.

In 2000, the Minnesota Zoo received the Association of Zoos and Aquariums’ Edward H. Bean Award for long-term propagation of the American pronghorn. 

Pronghorn as a species are not endangered, although subspecies found in the southwestern United States and Mexico are considered endangered.

Range and Habitat: The pronghorn is a prairie dweller, preferring flat, open areas or low rolling ground, and can withstand temperatures of 50 below to 100 F. Vast herds of pronghorn once ranged North America from southern Saskatchewan to the Pacific Ocean and as far south as Mexico. Today, small herds can be found in many states west of the Mississippi River.

Description
Pronghorn are horned, even-toed, hoofed, cud-chewing ungulates. The body is a rich tan with white under parts, white around the face, and a white rump. Horns grow just behind the eye socket. In males they curve back with a forward-pointing prong about half way up. Females have a small spike. Adult pronghorns are about 4 feet long and stand 32–40 inches at the shoulder. Bucks weigh 100–140 pounds; does are 10–20 pounds lighter.

Habits and Adaptations
In the winter, pronghorns form herds of 100 or more, and remain in a relatively small area if food and weather permit. They migrate along well-established routes, and generally travel single file.

Pronghorns can see for several miles. Their sense of hearing and smell are also very good. When alarmed, a pronghorn may walk as if its legs were coiled springs ready to let go at any moment. Its steps are measured and precise, almost as though it were stamping, and it raises the long white hairs on its rump to form a disc visible for miles. This warning is relayed from one animal to another until all pronghorns in the area are alerted to the danger. Pronghorns exude a musky odor from scent glands that can be smelled by other pronghorns far away.

Diet: Pronghorns eat grasses, forbs, and leaves, twigs, and bark of bushes. Sagebrush is a common food. They also eat alfalfa, crested wheat, and cacti (spines and all) when water is scarce. They need large quantities of food (4½–5½ pounds of sagebrush per day). They can go many days without water if necessary.

Breeding and Maturation
Pronghorns mate in mid-August to mid-October. The bucks drive the does into groups to form harems. Females may breed at an age of 16 months. Fawns, generally twins, are born in May or June after a 230- to 240-day gestation. Pronghorns live about 12 years in captivity and 8–10 years in the wild.

Locomotion
Pronghorns are the swiftest land animal in North America, and can maintain speeds of 45–55 mph for more than four miles. They have a remarkably smooth running gait. Their backs seem to remain level as their legs carry them across the roughest ground. It looks as if they are flowing across the earth without effort. When traveling at high speed, pronghorns cover the ground in great leaps; 14-foot jumps are common. Their running power comes from their well-muscled hindquarters. At times pronghorns bound with stiff legs rather than run smoothly. They frequently trot when they are not frightened but want to move a short distance in a hurry.

The pronghorn’s front legs maintain balance, helped by hooves that are larger than the rear ones. The front hooves of an average adult buck measure almost 3 inches from front to back, while the rear ones are nearly half an inch shorter. The cartilaginous padding is more pronounced on the front hooves than on the back. This padding cushions the feet against shock and prevents slipping while the pronghorn is traveling over rocky terrain.