Throughout the American West, long stretches of gravel and blacktop are often littered with roadkill. Just about anything can be found dead at roadside, including people, but you’ll probably find Big Foot roadkill before you find pronghorn antelope.
You can travel thousands of isolated backroads in the American West and never see pronghorn roadkill. As a science respecting skeptic, I believe all life got to be the way it is, and was, and will be, through evolution. That will not endear me to my Lakota elders, they probably have their own wakan inspired biography of the pronghorn, but to whatever extent evolution should be altering the risky behaviors of animals, adapting to make the respective phenotypes more competitive, you don’t see it at roadside.
Pronghorn must cross roads, and any person who has watched them do so, and the sight of a crossing is rare, sees them pick and choose their crossing. They aren’t just cautious: they appear to recognize opportunities far better than common roadkill species like raccoon and deer. My little tabby housecat looks both ways before crossing the road. We never took her to roadside as a kitten and taught her that trick. She just did it from the get. We had an orange tom, he never looked both ways. We don’t have that orange tom anymore.
So there are individual phenotypic differences, beyond the species level, which factor strongly in species behavior.
Evolution alters phenotypes over deep time, but we see no compelling evidence of this given the persistent levels of roadkill. No scientist knows for sure how long it will take fauna to adapt to the danger of roadkill, but the pronghorn, like my little tabby, never had to adapt from the get. Something made a critical number of pronghorn circumspect beyond what prairie fauna normally exhibit. Some ancient threat forced an evolutionary response over deep time.
John Byers wrote a book about “the Ghosts of Predators Past” in 1998, exploring the behavior and morphology of the pronghorn. The pronghorn has speed, in excess of 60 mph, and stamina, clearly not needed to elude even the wealth of predators around before the coming of Paleo-Indians over 10,000 years ago. Such characteristics evolved in the pronghorn for a reason, and they leave such a telltale signature they spark epiphanies of inquiry, resulting in a theory— perhaps there once was a predator, so threatening, the pronghorn needed these attributes to survive.
The fossil record has given up two extinct, and distinct American cheetahs. One species, Miracinonyx trumani, has the fossilized morphology of a super fast predator ideal for running down pronghorn. For over a million years she hunted the pronghorn across the American West, and mysteriously, like all the other Pleistocene megafauna, went abruptly extinct about 12,000 years ago.
We see this extinct feline as a failure, but she is wedded to this land far more intimately than any extant human being. The consequences of her existence resonate still today, every graceful herd of pronghorn we see scurrying outside our car window, informs any mind willing to investigate and understand, Miracinonyx trumani made pronghorn what they are, without her pronghorn would not exist, and so her legacy lives on in them.
I saw few pronghorn around the Black Hills as a boy. They are moving east from Wyoming sagebrush country, toward the Missouri River, and I think it is the growing desertification wrought by climate change prompting this expansion.
Because climate change is such a hot button political issue, scientific understanding eventuating from that climate change, will likely be scoffed at for some time. Besides, this pronghorn movement is occurring within the lifetime of most Americans, we have decades of hard research ahead before we can understand the extent and impetus prompting it.
Certain species have remarkably adaptive natures, like the coyote, who also seldom turns up as road kill. Now, more common than ever, he was a secondary predator before we eliminated the wolf. In Yellowstone, where the wolf has been reintroduced, coyote population has fallen, because the wolf kills any coyote he can.
Pronghorn move well through the world of men. They basically have the prairie to themselves, don’t have to share it with bison or wolves or large, well organized bands of aboriginal hunters. But none of their present day success would be possible had they not evolved the attributes to elude a long extinct predator.
(Contact James Giago Davies at firstname.lastname@example.org)