These graceful mammals are the only living animal with doubly-branched horns. Pronghorns are closely related to antelopes. They live in both small and large herds in western North American grasslands and semi-deserts .
Females give birth to twins in the spring.
Pronghorns have a life span of about 7 years in captivity. When a Pronghorn is alarmed, its hair stands up on end, revealing more white on its rump. Also, scent glands near the tail produce a stong-smelling liquid. These signals let other pronghorns know that danger is near. The scent glands are also used by males to mark territory.