Black Hills Wildlife: Pronghorn

Pronghorns are known by hunters as an incredibly difficult animal to catch, due to their incredible eyesight, stamina, and speed.

Published in 1844, trader Josiah Gregg wrote about pronghorns in his best-selling book about the West, Commerce of the Prairies. He refers to them as antelope in this selection, as they had not been classified separately at this point.

“That species of gazelle known as the antelope is very numerous upon the high plains.…The antelope is most remarkable for its fleetness: not bounding like the deer, but skimming over the ground as though upon skates.…The flesh of the antelope is, like that of the goat, rather coarse and but little esteemed: Consequently, no great efforts are made to take them. Being as wild as fleet, the hunting of them is very difficult.”

This animal can have a lifespan of about 10 years in the wild. They resemble antelopes, but there are many differences between the animals. They are characterized by their distinctive backward-curving horns, found on both males and females. The horns can grow to over a foot long.

Pronghorn can be from 30 to 35 inches tall, at the shoulder. Full-grown males can weigh up to 150 pounds, with males being 10% larger than females. They are herbivores and prefer to graze on flowering plants, although they will also eat scrubs, grasses, cactus, and crops depending on availability.

Pronghorn are a formidable catch for predators. They are one of the fastest mammals in North America, and can reach speeds of up to 53 miles per hour. This is not much slower than a cheetah, and pronghorns can maintain their speed much longer than a cheetah. They run with their mouths open so they can breathe enough oxygen to keep running.

Pronghorns have large eyes that allow them to spot predators from long distances. They can see movement as far as 3 miles away.

Before the west was colonized by Europeans, pronghorn population is estimated to have been 100 million. Due to habitat loss and overhunting, number dwindled to 13,000 left by 1920.

One hunting technique used by early settlers, called “flagging”, was to tie a piece of fabric to a pole and waved it in the area. The flag drew curious pronghorn within gunshot range. This technique is now illegal.

Due to conservation efforts, pronghorn now number between 500,000 and 1,000,000. The Sonoran pronghorn, however, is now down to a population of less than 1000. It is protected as an endangered species in Arizona and Mexico, and conservation plans are underway.

Pronghorn in the Black Hills can be seen in Custer State Park.

 

Trivia

  • The pronghorn is the second fastest land mammal in the world, after the cheetah.
  • They rarely jump fences and usually just crawl under instead.
  • Newborn pronghorns can walk after only 30 minutes and outrun a human after just a few days.
  • Pronghorn have the second longest land migration in the United States, after the caribou.
  • Herds migrate 150 miles each way between Wyoming’s Upper Green River Basin and Grand Teton National Park.