The pronghorn (Antilocapra americana) is not a true antelope but in a family by itself. It is native only to North America.
Pronghorns are the fastest running animal in North America. They can run at more than 53 miles an hour. Pronghorns are also great distance runners that can travel for miles at half that speed.
The pronghorn is the only North American big game animal that has branched horns, the horns split to form forward-pointing prongs that give the species its name. Pronghorns have true horns — derived from hair — not antlers. Pronghorns shed the hollow outer sheath each year in October or November and grow a new set by July. Both bucks and does have horns, but doe horns are shorter and more slender. Pronghorns are about three feet tall at the shoulders. Bucks weigh about 110 pounds. Pronghorns have a bright reddish-tan coat marked with white and black. The buck has a conspicuous black neck patch below the ears, which is lacking on the doe. At a distance, their markings break up the outline of their body, making them difficult to see. Their white rump patch is enlarged and conspicuous when they are alarmed. The flash of white serves as a warning signal to other pronghorns and is visible at long distances.
Each fall bucks gather harems of females and protect them jealously—sometimes battling rivals in spectacular and dangerous fights. In the spring, females give birth to one or two young, which can outrun a human after just a few days.