Despite being the fastest land mammal on the continent, pronghorn are constantly on the look out for threats. If speed is its first defense, then sight is the second best protection from predators. With its exceptionally large eyes set far back on the skull it can detect movements up to five kilometers away, the same as eight-power binoculars. The eye placement also provides pronghorn with an exceptionally wide field of vision, which is crucial to life on the open plains.
During his historic travels, Meriwether Lewis was especially struck by the eyes, which were “large and prominent.” The pupils were “deep sea green, large percing and reather prominent, & at or near the root of the horn within one ¼ inches.” Even a pronghorn’s long eyelashes have a purpose for prairie life beyond beauty — effectively shading its eyes from the sun.
Photo: Dennis Lingohr/APR