Pronghorns live in the open prairie, a place where speed is essential for survival. They are the fastest hoofed animal in the world, running at 30 mph (50km/h), but reaching over 50 mph (80km/h) in short bursts. They run with long bounds on their slender legs and they have a habit of shaking themselves when they come to a halt. Pronghorns are easy to spot because they have distinct brown and white markings; their horns are nearly black. Pronghorns are classified in a family by themselves. Unlike their antelope and deer relatives, pronghorns shed their horns and grow a new set every year. Before Europeans arrived in North America, there were more than 30 million pronghorns roaming the prairies. Farming and hunting reduced those numbers to 20,000 by the 1920s. Now, pronghorns are a protected species and their numbers have recovered to about one million.