Male antelope, or bucks, have horns about a foot long, with prongs that curve at the tips. Mature females, or does, have horns as well. However, their horns are much smaller and average about two inches long. The fork in antelope horns is characteristic of antlers, and this is what part of makes antelope unique. It's the only animal to have branched horns, which is how it gets the name "Pronghorn Antelope." Another unique aspect of antelope: the shed their horn sheaths each year, and are the only horned animal to do so. How about another interesting tidbit? Believe it or not, the antelope's closest genetic cousin is in Africa. Genetically, antelope are more similar to Thompson's Gazelles than they are to any ungulate in North America Bucks are usually larger, weighing around 125 pounds; does weigh around 100. The bucks are fairly territorial in the spring, summer and fall, but join the herd to forage in winter. Herds may roam many miles in search of food. Does usually have two fawns per year that stand up and learn to and run within a few minutes of being born; at just four days old they can keep up with the herd. Antelope are easy to spot because they live in the open prairie all across the eastern two-thirds of Montana.