Our daughter Hannah Virginia saw her first pronghorn during the week of her second birthday. It was early April, and the wind swept light snow around the sage and rabbitbrush as I shoved her three-wheeled stroller up a sandy draw a few miles from our house. The sky was cloudless, that shimmering azure that distinguishes winter days in the high desert, and we were surrounded by last season’s balsamroot rattling stiffly in the wind. As I dug the toes of my boots into the snow to get traction enough to push Hannah uphill through a thick stand of desert peach, she suddenly took the pacifier out of her mouth with her left hand, pointed to the southern horizon with her right, and said, “Moon.” At that age she loved to find the moon, just as her little sister does now, and she often spotted the thinnest crescent even in the brightest sky. “Good job, honey,” I said routinely, keeping my eyes on the terrain ahead and pushing hard. “Daddy, moon!” Her tone was so urgent that I stopped pushing, knelt next to the stroller, and looked with her into the southern sky, where I saw nothing but blue depth and distant mountains. Then I noticed that beneath the sky, where no moon hung, two pronghorn does stood on a ridgeline several hundred yards away, staring directly at us. Hannah was not saying “moon” but, rather, “moo,” which was apparently shorthand for “big, nonhuman mammal.”

Hannah again said “Moo!” and one of the does responded with a breathy snort, “cha-oo.” Hannah’s extended arm shot down into her lap, and she whipped her head toward me with eyes as big as a fawn’s. This was the “Dad, what the hell?” look of alarmed joy that she gave me every time we saw a miracle in the desert, which was often. When I smiled, Hannah turned back toward the pronghorn, leaned forward in her stroller, and yelled “Moo!” again into the wind. The second doe replied: “Cha-oo!” Now Hannah was thrilled, and she began flapping her arms like a magpie, shouting “Moo! Moo! Moo!” at the pronghorn as they stood frozen against the moonless sky. And then she stopped and held absolutely still, listening intently. The sound of the wind seemed more textured than before, surging and lilting like invisible surf. The dry leaves scraped as though we were hearing them through a stethoscope. Again: “Cha-oo. Cha-oo.” Hannah grinned, wide-eyed. And then the two does eased a few steps back and were out of sight on the other side of the ridge. In another five weeks they would each give birth to twin fawns, somewhere out there.

We live at six thousand feet on a wind-ripped hilltop in the western Great Basin Desert, on the eastern slope of the Sierra Nevada, in the broken, sagebrush steppe and high valleys on the northern Nevada-California line. It is a land of leopard lizards and golden eagles, packrats and ravens, jackrabbits and mountain bluebirds. Our home mountain, which is three miles to our west and looms two thousand feet above us, has California on its far shoulder. We are only twenty miles from Reno, a city of more than four hundred thousand people, and in fact are only twelve miles from the nearest casino. Nevertheless, much of the country around us is public land managed by the Bureau of Land Management (BLM). And while the BLM is so poorly funded that its ability to manage much of anything is ever in question, the fact that public lands exist this close to the city has made it possible for quadruped big mammals to live here too; we feel fortunate that our kids are growing up in a place that remains wild enough to support not only Old Man Coyote, but also mule deer, bobcats, mountain lions, and pronghorn.

Although I am admittedly lococentric and thus strongly biased in favor of my own neighbors, to my mind the pronghorn is the most charismatic of megafauna. It is very unlike any other species in the world, and that is because it is—among the many antelope-like ungulates that once inhabited the prairies of prehistoric North America—the sole survivor of the Pleistocene extinctions that erased three-quarters of this continent’s large mammals around eleven thousand years ago. Antilocapra americana is alone in its genus because it is a relict of the late Cenozoic savanna. The pronghorn is a true North American native, having evolved here over the past twenty million years or so. Sometimes called the “prairie ghost” for its elusiveness and speed, the pronghorn is also the ghost of evolution itself. It is all that remains of at least twelve distinct pronghorn-like genera of animals that once inhabited the ancient prairies—some species with two horns, some with four, some six, some with branching horns, others with horns that spiraled fantastically to a point. Of what were probably dozens of species of Antilocaprids, only the pronghorn has survived the crucible of evolution. Survived may be too grim a word for so beautiful a product of so beautiful a process. Say instead that pronghorn have been turned on the lathe of evolution for twenty million years, sculpted by predator and place, fired in evolution’s prairie and desert furnace. Seen in the light of its evolutionary history, pronghorn is not a thing but rather an outcome—one as inevitable as it was unlikely.

The evolutionary adaptations that these living Paleolithic ghosts made to prairie and desert environments are many and remarkable. Their coloration is tawny as dust, and their tan neck is garlanded at the throat with a white shield, and higher up with a crescent ring, creating a broken tan-white pattern of camouflaging so effective that when a pronghorn turns to look at you it often seems magically to disappear. Bucks have elegant black patches from the ears downward beneath the chin, and older, stronger males have intimidating black masks that sometimes completely cover their eyes. Pronghorn hair, whatever color it may be, is adapted to allow the animal to endure almost inconceivable extremes of heat and cold, from 50 below zero in winter, in the northern part of its range on the windswept Canadian prairies, to summer temperatures of 120 degrees or more, in the scorching deserts of the Southwest and Mexico. Each hair is perfectly insulated, spongy and air-filled, and can be flattened to create a waterproof and windproof shield, in winter, or lifted to allow heat dissipation, in summer. The bright white hairs on the rump are controlled by an extreme form of the same process of piloerection that makes the hair on the back of your neck stand up when you’re hiking in grizzly country. These three-inch-long hairs, when flared, make the rump appear larger and brighter than usual, and so function as a warning signal to other pronghorn, especially in flight. Illuminated in the brittle glare of the high desert sun, these distinctive white patches are often visible from miles away, and I have seen them glide across a distant hillside long after the rest of the animal had vanished into the sage-dotted land.

While pronghorn females sometimes grow short horns, males carry the distinctive pronged horns, which may grow to twenty inches long, and are used as weapons against competing bucks during the autumn rut. These cranial meat hooks are so powerful and sharp that the mortality rate in full-out buck fights sometimes runs to 10 percent or higher. The horn of the pronghorn is not an antler; while antlers are shed each year and are made of bone, horns are kept for life and consist of keratin—the same material used to build hair and hooves. Yet even here the pronghorn is anomalous. Not only is it the only animal in the world with horns that branch, but it is also the only animal that sheds its horns annually—or, to be more precise, sheds the keratinous sheath that covers the horn’s bony core. Although this odd combination of antler and horn qualities has resulted in the pronghorn’s imprecise genus name, Antilocapra, which means “antelope goat,” the pronghorn is neither antelope nor goat. Most of the several hundred recorded Native American names for pronghorn are more elegant and accurate. Many, including those of the Indian peoples who have long lived in this region, mimic the pronghorn’s breathy snorts. The Northern Paiute of nearby Honey Lake and Surprise Valley, for instance, call the pronghorn dü’ná; to the Western Shoshone of central Nevada, Antilocapra americana is wahn’-ze; it is called á-yĭs by the Washoe of the eastern Sierra.

Considering that pronghorn are fairly small bodied, with adults typically weighing not much more than a hundred pounds, their eyes are unusually large—almost as large as an elephant’s—an adaptation that allows them to see great distances across open landscapes. While they have good hearing and a decent sense of smell, it is their superb vision that they depend on most, a fact that became clear to me the first time I spooked pronghorn from two miles downwind. The animal’s large black eyes are unusually high in the head and far apart, socketed in bony turrets that allow for nearly panoramic vision. Because pronghorn are native to shortgrass prairie and desert, where cover is low, the high placement of their eyes allows them to scan for cruising predators even as they forage.
 

Pronghorn are such choosy and itinerant browsers that you can approach an area where they have been feeding and find no sign of cropped plants. Far from being the rototillers or weed wackers so common among ungulates, pronghorn snip individual leaves and stems so selectively that their presence on the range is barely discernible. This discriminating browsing for vascular forbs is also related to their ability to survive with so little water, even in conditions that immediately threaten dehydration for other desert mammals. While pronghorn prefer to drink some free water, they can manage to derive most—or, under extreme conditions, all—of their water from the plants they so carefully select. And, as a ruminant, the pronghorn has a four-chambered stomach, the second chamber of which (the “rumen-reticulum”) is loaded with bacteria, protozoa, and fungi that digest cellulose and other plant material that the standard-issue mammalian gastric system can’t handle. Pronghorn have coevolved with the micro-beasties in their gut, creating an ecosystem within an ecosystem without which they would starve. All of these formidable adaptations to the often fatal extremes of their home environments have been crafted by twenty million years of trial and error in which error soundly dominated. Nevertheless, only a few successes are necessary if you have twenty million years to perfect them. The pronghorn we see today are what remains after millions of years of errors have been culled from the gene pool, each error chipped away until the sculpted form of this evolutionary ghost emerged from the unhewn rock of ages.-only twenty million years old. An eco-critic details the progress of North America's speediest megafauna and the human advances that threaten it.

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