Pronghorn

Back on February 17 I had the good fortune to be invited on a road trip to Sierra Vista, Arizona by my friend Margarethe Brummermann. We were on our way to visit our mutual friend Pat Sullivan, and his wife Lisa Lee, when we were delighted to spot a small herd of pronghorn, Antilocapra americana.

Most of us here in the U.S. grew up learning this animal as the “pronghorn antelope,” but the truth is that this mammal is in a class by itself. Well, a family at least, and is not at all a true antelope.

Margarethe spotted this herd along Arizona state route 83, just north of the welcome sign for Sonoita. They are probably the subspecies known as the Chihuahuan pronghorn, A. a. mexicana, according to this wonderful article on the ”Firefly Forest” website run by T. Beth Kinsey. Reintroduced to Arizona from Texas, they seem to be acclimating well here.

One aspect of pronghorn biology not in dispute is their legendary speed. The fastest thing on four legs in North America, they can run well over forty (40) miles per hour (70+ km/hr), and sustain that sprint long enough to outlast any potential predator. In fact, one of their few enemies is the golden eagle. Reports of pronghorn clocked at over 60 mph may be an exaggeration, but not by much.

We expected that the herd we were observing would bolt as soon as one saw us, but such was not the case. It was sometimes even difficult to get their attention by whistling at them, so intent were they on grazing. The backdrop of the snow-dusted Santa Rita Mountains made the whole experience even more spectacular.

Back to pronghorn biology for a minute. Both genders can sport horns, er, antlers….Well, there you go again, another enigmatic aspect of this animal. Technically speaking they do have horns, but they are covered in black sheaths that are shed like antlers. Males have the forward-projecting “prong,” while the female lacks this feature. She sometimes lacks the horns altogether, in fact.

One of the best accounts I have ever read about pronghorn is by Daniel Mathews in his book Rocky Mountain Natural History (Raven Editions, 2003). He details the evolution of the species, and the maternal strategies of the females, in literary prose I cannot hope to duplicate. If it is possible to push the pronghorn mystique beyond the level of western grassland icon that it already is, Mathews has achieved that.

I, for one, am deeply grateful to state and federal wildlife agencies and personnel for insuring that this species is sustained as a piece of living history, reminding us of the true meaning of freedom and open spaces. Pronghorn truly exemplify the term “natural history.”