Pronghorn: Americas speed demon
The pronghorn is a peculiar critter. Often called an antelope, pronghorns are not related to antelope from Europe or Africa. In fact, they are the only animal in the genus Antilocapra. They are related to goats and are sometimes called “speed goats.”
Pronghorns are the only animal in the world that grows horns that are branched, hence their name. They are also the only animal that sheds its horns each year.
They are one of the fastest animals in the world and can run for miles at speeds of 50 miles per hour.
Pronghorns are popular with wildlife watchers because the open habitat they live in makes them easier to see. Their striking coloration makes them a beautiful sight and their blazing speed make them fun to watch.
What is the difference between antlers and horns?
Antlers are found on members of the deer family and are usually grown only by males. They are a bone-like growth that is shed and re-grown every year. Antlers are usually branched and have multiple points.
Horns are grown by members of the sheep, goat and cattle families. They are made of a sheath of specialized hair follicles that grow over a bone core. Horns are not shed, but continue to grow throughout the life of the animal. Both males and females grow horns, but the horns grown by males are usually much larger. Horns do not usually fork or branch.
THE EXCEPTION TO THE RULE
As it’s name implies, the pronghorn grows a horn that has a prong or branch. Sometimes incorrectly called an antelope, the pronghorn is also different because it sheds its horn sheaths every year.
Both the buck and doe pronghorn have horns, but those of the buck (shown above left) are much bigger and have a prong. Males also have a black cheek patch and a darker nose than females (shown above right).
Because pronghorns live in open country, vision is an important part of their survival. Their large eyes protrude from the side of their heads. Some scientists believe that Pronghorn eyesight is comparable to our eyes looking through 8-power binoculars.
Since vision is so important, pronghorns are usually most active during the day when bright sunlight makes it easier to see.
Another adaptation that helps pronghorns is that their hair is hollow. This provides excellent insulation to help keep them cool in the summer and warm during the cold and windy winters of the high plateaus.
Built in binoculars
Coyotes are one of the predators that pronghorns need to watch out for. If pronghorn eyesight is equal to 8-power binoculars, the coyote on the right would look more like the coyote above left to a pronghorn. making it much easier to avoid these crafty predators.
In Wyoming and northern Colorado there are more pronghorns than people.
Pronghorns are often found in small groups with a dozen or so does and a buck or two. Breeding occurs during the fall. Females typically give birth in the spring to two babies called fawns or kids (just like baby goats). Pronghorn kids can get to their feet within minutes of birth and within a day or two can outrun a coyote.
Nearly all pronghorn populations are found in open, low rolling, or flat terrain with a good supply of sagebrush and other shrubs.
Because pronghorns inhabit the high plains deserts, drinking water sources are important to pronghorn populations. Although pronghorns can get most of the water they need from the plants they eat during wetter periods, when things get drier they need ponds and springs to supply them with the gallon of water they need every day.
In Wyoming’s Red Desert, 95% of 12,465 pronghorn counted from the air were within 4 miles of a water source.
Animals that are active during the day, like pronghorns, are called diurnal. Nocturnal is the word used to describe animals that are active at night. Many of Utah’s big game animals, especially deer and elk, are most active during the twilight hours around dawn and dusk. The word that describes this type of activity is crepuscular. Many animals that are called nocturnal are in fact crepuscular.
Being active at different times allows different animals to use the same habitat without being in direct competition. Hawks and owls can hunt the same field or meadow for the same rodents without conflict because hawks are diurnal and owls are nocturnal.
Being active at night is an adaptation to avoid or enhance predation. For example, lions prefer to hunt at night because many of the animals they eat like zebra and impala don’t see well at night. Many species of small rodents are active at night because most of the birds that hunt them are diurnal.
Some animals, like the lion or even a domestic cat, can be active at all times of the day. They have specially adapted eyes that let them see both day and night. They choose when to hunt based on the availability of prey and temperature or weather factors.
In the 1960s, 129 pronghorns from Montana were transplanted to Parker Mountain in central Utah. Since that time, the herd has become one of the most prolific big game herds in the nation. Since 1975, the Parker Mountain pronghorn population has provided over 4,700 pronghorn for release into areas throughout Utah, and other western states.
Pronghorn populations in Utah during the early 1900’s were located in the west desert from Beaver County north to the Idaho state line and in Daggett County in northeastern Utah adjacent to the Wyoming state line. Beginning in 1945, transplants of pronghorn to other areas in the state have resulted in a wider distribution in most of Utah’s suitable desert habitats and have increased the statewide population to an estimated 12,000–14,000 animals.
Most of Utah’s pronghorn herds are a result of transplants. Although few areas of unoccupied pronghorn habitat remain in the state, it is important to continue to use surplus animals from selected units to augment existing populations during times of low production.