Adult pronghorns lock horns in Lamar Valley while a youngster looks on.
American pronghorns have horns, not antlers. Their horns are unique because they have a bony core covered by a sheath made of keratin (the same material as fingernails). Unlike antlers, which are shed annually by animals like elk and moose, pronghorns shed the outer keratin sheath of their horns each year but retain the bony core. This makes pronghorn horns distinct from the permanent horns of other horned animals, such as mountain goats, and different from antlers, which are fully shed and regrown annually.
