PRONGHORNS SURVIVORS FROM A LOST WORLD

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“From the accounts of all the Indians, I have seen, it is probable there may be a species of Antilope near the head waters of R. River.” Those words, penned for the eye of President Thomas Jefferson, were written by Dr. Peter Custis, the official naturalist attached to Jefferson’s “Grand Expedition,” the president’s follow-up to the Lewis and Clark exploring expedition into the Louisiana Purchase. When Custis conveyed to Jefferson accounts from the Indians and their guides about the mysteries that lay farther up the Red River of the Southwest, he was writing at one of the portentous moments in the early exploration of the West. His brief line, it turned out, also captured a critical point in time in the long history of one of the true marvels of the American Great Plains, the pronghorn antelope.

The year was 1806, and Custis was with a fifty-man party of scientists, soldiers, and guides that had just been turned back at the edge of the Great Plains by a Spanish army. In almost a final, dying gasp of its North American empire, Spain had risen to the occasion to keep expansionist-minded Americans out of the Southwest and away from Spanish treasures like Santa Fe and the California missions. Naturalist Custis was taking one last wistful look upriver before heading back to civilization. And one of the misses on his mind clearly was this rumored, African-like “Antilope” that roamed the horizontal yellow prairies just beyond his reach as an Enlightenment Age scientist.

When Americans finally made it to the Great Plains at the turn of the nineteenth century, we called these fabled animals antelope for good reason, since in size, form, and speed they resembled no other creatures quite so much as the antelopes and gazelles of Africa. But pronghorns turned out not to be true antelope. The Antilocapridae (“antelope-goats”) emerged as a distinctly American family of animals roughly 25 million years ago, but paleontologists still do not agree on their earlier provenance. An older super-family, the Cervoidea, may have produced both the Antilocapridae and the Cervidae (the deer family), but there are some modern biologists who argue for an Asian bovine line of ancestry for pronghorns. Others think their closest living relatives are in the family Giraffidae—the giraffes, whose legs resemble pronghorn legs.

Pronghorns evolved on the Great Plains with 70 mph predators like American cheetahs. When their predators vanished in the Pleistocene extinctions, pronghorns continued into our own time with evolutionary adaptations modeled around a vanished world. Dan Flores photo.

Whatever their origins in ancient America, modern pronghorns are a rarity in nature, a species that is today the sole remaining survivor of an entire family of animals. Fossil records in North America demonstrate that the Antilocapridae actually consisted of two major subfamilies. The earlier of these subfamilies, the Merycodontinae, or “pronglets,” included several species of graceful, dainty ungulates with teeth that were very different from deer, but possessed of permanent, multi-branched, antler-like horns. The various species of the exotic little Merycodontinae were all extinct by the end of the Miocene, around 5.3 million years ago, but their line had given rise to the other subfamily, the Antilocaprinae, which soon replaced them on the great grasslands that were emerging in western America. The various species of Antilocaprinae were larger “antelope-goats,” very definitely high-speed runners still, but with quite different horns made around a deciduous sheath. Some Antilocaprinae species sported four and sometimes six of these horns, whose sheaths (but not the cores) were shed annually. One dwarfed four-horned version, Tetrameryx, not much larger than a jackrabbit, still sprinted across the Great Plains as late as 10,000 years ago but vanished soon after. Very rarely four-horned animals are still born to modern pronghorns as genetic reminders of this varied deep past. But Antilocapra americana, our present-day pronghorn from an evolutionary family dating back 25 million years, is now the single living representative of the entire family—consisting of two subfamilies, at least fourteen genera, and many dozens of species—of the Antilocapridae.

In 1997 biologist John Byers, after years of studying pronghorn behavior and natural history on western Montana’s National Bison Range, offered up a provocative argument that explained much about an animal that has long seemed somehow inexplicable, almost “alien,” even to its admirers. Pronghorn watchers had long noted the animals’ inability to jump fences and attributed it to pronghorn evolution. A grasslands creature shaped by the open country niche it occupied, pronghorns never experienced any selective pressures to be able to jump obstacles, which ultimately became a maladaptation to the modern world that played a central role in pronghorn history across the past 150 years. Byers found many other deep-time adaptations that help explain pronghorn oddities on the modern plains.

Pronghorns are one of only a handful of Great Plains species that managed to survive the truly epic extinction crash that ended the Pleistocene 10,000 years ago, a bestiary simplification that stands as the most profound ecological alteration in western North America since the extinction of the dinosaurs. In the biography of this species, however, the Pleistocene extinctions were only a few heartbeats in the past. So what if much about the behavior of modern pronghorns has little at all to do with the present circumstances of the plains? What if most of their physical characteristics and behavior are adaptations to a lost world that winked out around them 10,000 years ago, leaving pronghorns still living out their existence among us reacting to a world of ghosts?

The primary predators of pronghorns for the past 10 millennia have been wolves and coyotes, neither of which is capable, flat-out, of running more than 45 mph. Pronghorns, on the other hand, are the Ferraris of the natural world. Their delicate bones and frames and remarkably low body fat keep them light, while broad nostrils and a huge windpipe deliver turbocharged oxygen to their outsized lungs and heart. Pedal-to-the-metal they top 85 kilometers per hour, some 55 mph for the 120-pound males and possibly as high as 65–70 mph for slighter females, which is as fast as the cheetah. They can run at 90 percent of top end for more than two miles. Like horses, to detect predators at great distances they evolved gigantic eyes. But why so much protective excess?

Pronghorn behavior features other peculiarities. Like Thompson’s gazelles and other African ungulates pursued by big cats, pronghorns have a powerful inclination towards a form of grouping known as the selfish herd, with much of their expression of dominance and rank focused on their physical position inside the groups. The lower-ranking, less dominant animals get pushed to the outer margins where, if pronghorns were on the African veld, the low-ranking group members would be in much greater danger from predatory attacks. But as adults, American pronghorns have no predators. Because of their impossible speed once they’re grown, pronghorns are subject to predation only as fawns. If a pronghorn fawn survives to six or eight months of age it will join all other surviving fawns in living to the ripe old age of eleven or twelve years old. Yet pronghorns still group, and fight for position in the center of them, and persist in joining groups as if predation mattered when (except for fawns) it simply doesn’t.

The fascinating question, then, is whether the whole suite of pronghorn behaviors, not just their lack of jumping ability, has something to do with the lost world of the Pleistocene Great Plains? Pronghorns emerged in their modern form at a time when the American Great Plains was the scene of one of the grandest assemblages of savanna-steppe creatures anywhere on earth, a more diverse collection of animals than are present in the African Serengeti or Masai Mara today. Along with the elephants and long-horned bison and the enormous herds of horses and zebras, along with bands of numerous types of camels and deer, and of course elk and pronghorns, the Pleistocene Great Plains of the past 2–4 million years featured an array of truly formidable predators that hunted and scavenged among the millions of ungulates. Pronghorns spent the better part of 4 million years perfecting their ability to survive where large and fast predators looked hungrily at them over bright teeth.

There were gracile, active, and aggressive short-faced bears (Arctodus simus), the Smilodons or saber-toothed cats that attacked mammoth calves, and a steadily changing lineup of wolf and coyote packs. Jaguars and cougars were present, along with the steppe lion (Panthera leo atrox), a far larger version of the African lion. Predators of the fastest grazers, the horses and pronghorns, included a slender-limbed, lion-sized running cat known as the scimitar cat (Homotherium serum), along with a particularly rapid and leggy American “hunting” hyena, Chasmaporthetes ossifragus. And there were two species of large American “false” cheetahs, Miracinonyx trumani and M. inexpectatus, cats from the same evolutionary line that produced cougars, but with elongated, curved spines, long legs, and wide nostrils for gulping air in open country pursuit or in rockslide ambushes.

These vanished creatures of the ancient plains—so biologists have begun to argue—however long ago they passed the veil of extinction, are the cause for why pronghorns seem so alien and unusual to us now, why they struck early observers like Lewis and Clark as possessing a speed that resembled more the flight of birds than anything else. Pronghorns are at once breathtakingly beautiful yet outrageously overbuilt relicts that have outlasted the conditions that created them. They offer almost our only remaining glimpse of the American Pleistocene.

Like most wild ungulates then, or now, pronghorns follow a route that varies considerably by the seasons. At the conclusion of the September rut, the exhausted bucks, which would once have been prime targets for predators, disguise themselves by mimicking the females. They shed the outer husk of their horns and join the female herds. Since the Pleistocene, winter has been a time of migration for northern pronghorns. A few years ago, with a friend who lives in Jackson Hole, I photographed the famous Sublette pronghorn herd, which summers in Grand Teton National Park but still migrates almost 200 miles south, near Green River, Wyoming, in winter. This inclination to migrate before severe winter storms was adaptive in the wild, but coupled with their inability to jump obstacles ultimately would produce tragic die-offs in the late nineteenth century, when legendary winters in the 1880s sent pronghorns southward by the thousands into a new era of barbed-wire strung across the plains.

In the spring, from a year old until they are three, young pronghorn bucks segregate themselves into bachelor bands and spend most of their time in all-male groups. There they express group position dominance just as females do, but they also spar and practice moves they will later use in earnest. Around three years of age, pronghorn males become solitary for most of the spring and summer, during which time—at least in most pronghorn country—they set up territories of perhaps 150 acres whose perimeter they scent-mark and will use to cloister a harem of females to hide from other males during the rut. In other circumstances, male pronghorns protect harems of females but without defending a territory itself. Rather than a prime resource location, pronghorn territories seem to be merely tactical space for defending females. Pronghorn bucks fight over females, too, in violent, quick, and quite often mortal (as high as 15 percent of the encounters) fights. Reproduction success is the prime directive, and some pronghorn bucks win the lottery. Others spend their entire lives without ever siring any offspring at all.

Then there is female selection behavior. Female pronghorns, which reach sexual maturity at eighteen months of age and give birth every spring for the rest of their lives, find themselves in harems that male pronghorns judiciously protect during the brief September mating season. During the rut females repeatedly break away from their cloistered harems, however, joining the other harems of other males and inviting males to compete for them. What are they looking for? Apparently they are setting up contests of stamina, speed, and resolve between various males and observing the outcome before surrendering themselves up to be bred by “the winner”—the pronghorn male that demonstrates his genetic fitness by running faster and longer than his rivals. But if you are already almost 20 mph faster than your fastest predators, why would females set up games of natural selection and choose who will impregnate them based on fitness as demonstrated by speed?

Pronghorn females have evolved another strategy that is interesting with respect to what it says about both past and present. After a remarkably long gestation period of some 252 days, they give birth not to single offspring but to “litters,” specifically litters of two fawns every spring, and do this throughout their reproductive lives. Twinning as well as the weeks-long “hiding” of fawns, which lie motionless and silent for most of a day, are clearly responses to serious predation and they, too, probably emerged as adaptations to the distant past, when pronghorns lived in a world where they were prey for three or four different predators. Today it means that coyotes, the principal predators of pronghorn fawns for probably the last million years, are able to pull down as much as 50 percent of a pronghorn fawn crop, sometimes as much as 70–80 percent, without appreciably affecting pronghorn populations. With “litters” and with their extremely high adult survivability rates, pronghorns were anciently prepared to survive the culling of even so efficient a predator of fawns as coyotes.

With no predators in adulthood but shrewd coyotes as predators of their fawns, pronghorn females commonly give birth to twin fawns as insurance. Dan Flores photo.

While a mother pronghorn will attack and fight a coyote to keep it from her fawns, pronghorn bucks do not defend fawns. Some biologists argue that this is another leftover behavior from the Pleistocene, when fast predators scattered groups of pronghorns across wide territories and a male pronghorn thus could not be sure that a fawn it defended was its own.

As cud-chewing ruminants capable of processing forbs and shrubs, pronghorns demonstrate yet another adaptation to the ancient savanna ecology of western America. For at least 800,000 years, since bison had followed the Bering land bridge from Asia into America, pronghorns had been evolving a mutualistic relationship with the bison herds. Bison, too—albeit a smaller, shorter-horned, “dwarf” species of them—had survived the Pleistocene extinctions and had increased dramatically in their wake, in numbers (depending on the climate cycles) that likely ranged somewhere between 20 and 30 million animals. Waves of bison and waves of pronghorns cropping the same country produced mutually beneficial results. Cropping the grasses and ignoring the often-poisonous species like locoweed, rabbitbrush, and sagebrush, bison grazing encouraged forbs and shrubs in their wake. Coming along after the bison herds and concentrating on the flowering plants and shrubs, pronghorn browsing shifted the advantage back to the grasses. Both preferred areas that were freshly burned, when pronghorns would avidly crop new grasses, too.

Thus deep-time history created an entirely unique situation for pronghorn antelope. Since pronghorns had out-survived almost all their predators, had ended up with few competitors for the often toxic shrubs and forbs they preferred, they spread everywhere there were vast, horizontal yellow plains, and they increased into the millions. Ernest Thompson Seton famously estimated that in 1800, the moment in time when pronghorns were on the verge of discovery by formal western science, there were 40 million of them in America. More recent estimates have advanced original figures of 15 to 35 million. But all these are wild guesses, as no one then or now can say with any certainty. What we probably can say is that on the Great Plains, where their ranges overlapped most precisely, pronghorn numbers very likely matched those of bison. We’ve long thought of the historic-era Great Plains as the Great Bison Belt. In truth it was just as much the Great Pronghorn Savanna.

Nineteenth-century exploration and travel literature speaks of bison and pronghorns so often as a matched set on the Great Plains that we’ve tended to imagine them as co-inhabitants of the West, but actually their ranges were not identical. Pronghorn bands and bison herds created their mutualistic foraging pattern on the Great Plains, but the two iconic prairie animals spilled in different cardinal directions on the continent. Bison were able to graze mid-height grasses like little bluestem and to a lesser extent the knee-high bunchgrasses west of the Rockies. When the climate was favorable and times flush on the plains, overflow bison populations could pool westward but primarily went eastward, to the Mississippi River and even beyond it.

Pronghorns, by contrast, are animals of the shortgrass plains and desert grasslands. They don’t appear to have advanced eastward beyond about the 97th meridian in Texas and Mexico and the 93rd meridian (into Iowa and Minnesota) farther north, but ranged westward all the way to Baja California and eastern Oregon and Washington. Better adapted to tundra climates, bison survived winters much better on the Canadian plains than pronghorns. But southward on the continent, pronghorns were able to colonize the desert grasslands of Mexico all the way to the vicinity of Mexico City at 20 degrees latitude, considerably south of where bison ever ventured. Although pronghorns can derive adequate water from the plants they browse in optimal, wet conditions, contrary to rumors about them, they need to drink about 3½ quarts of water a day during hot weather, which limited their numbers in the Great Basin and the Mojave, Chihuahuan, and Sonoran deserts.

The truth is that, as with their evolutionary behavior, we have only recently come to understand something about the role pronghorns played in the Indian world in the West in the 10,000 years after the Pleistocene extinctions. Abundant and widespread, they attracted the attention of Indian hunters from the beginning. There are butchered pronghorn remains in some of the Clovis and Folsom archaeological sites, particularly those around lakes and marshes on the plains, so at least some Paleo-hunters did take the occasional pronghorn to vary a diet of mammoth cuts and steaks from giant bison. But it required fifteen to twenty pronghorns to equal the caloric possibilities of a single giant bison, and since pronghorn flesh was so very lean, pronghorns commonly ranked well down the list of commonly pursued prey. Among Southwestern peoples pronghorns ranked lower than rabbits, even though it took sixteen jackrabbits to match the edible flesh of a pronghorn.

Archaic hunter-gatherers and even historic-era Indian hunters, understanding from hundreds of generations of experience with pronghorns how to exploit their weaknesses, nonetheless killed them in large numbers and utilized pronghorn leather, horns, and hooves for a variety of purposes. One aspect of pronghorn evolution that made them vulnerable to Indian hunters was their inability to jump. Another was their disinclination to leave their home ranges. That deep cultural lore meant that even foot-bound Indians long ago figured out techniques for hunting pronghorns successfully. Parts of the West yet show fading evidence of ancient pronghorn corrals such as the Fort Bridger trap site in southwestern Wyoming, where local Indians enclosed pronghorn herds and pushed them to run in circles until they were exhausted and could be clubbed to death. Another technique involved a V-shaped pair of fence wings, often miles long, made from piled-up sagebrush that sent stampeded pronghorns into corrals or pits.

There are also references from a variety of sources of horse-mounted Plains Indians engaging in the kind of historic “surround” often used for bison to hunt pronghorns successfully, again with the goal of getting a pronghorn band to run in circles until the hunters could ride down the spent and stumbling animals with their horses. According to Richard Irving Dodge, when pronghorns collected into the thousands in wintertime, some tribes even used rifles in pronghorn hunts from horseback. Reacting as if pursued by predators, the “antelope crowd together in their fright,” Dodge wrote, and hunters easily shot them down. Because local herds could end up completely extirpated by mass techniques like these, hunters among the Navajos often spared a couple of animals.

When bison were scarce, plains hunters preferred antelope to deer because you could take an entire herd of pronghorns at once, but a small hunting party might prefer to jog an individual pronghorn to exhaustion by relentlessly pursuing it on foot, or lure always-curious antelope within gunshot range by waving flags or performing odd gymnastics. Whatever the technique, the problem of lack of fat remained. Unlike bison or elk, pronghorns butchered out as all protein and very little precious fat. Their lean body mass may be the reason no tribe bothered to domesticate pronghorns, which are easier to tame than any African antelope.

Leather was certainly tanned from pronghorn skins, but both Indians and white market hunters thought antelope hides were inferior to those of bison or deer. Nonetheless, when Thomas Jefferson’s Indian agent for the Orleans Territory, Dr. John Sibley, held a council for the Southern Plains tribes in Natchitoches in 1807, among the group that assembled was a soon-famous plains tribe, the Comanches, who had a division known as the Kwahadis or Antelopes. Sibley went on to write that “they dress the skins of the Antelope most beautifully and Colour them of every shade from light Pink to Black of which they make their own and Husbands Clothing, the edges Pinked and scalloped resembling lace. . . . you would take them for fine Black velvet.”

The Indian peoples of the West had thus known pronghorns intimately for thousands of years. Among Europeans it was the numerous Spanish travelers on the Great Plains and in California who first encountered them and called them berrendos, while French travelers all across the Great Plains referred to them as chevreuilles or cul blanc. Francisco Hernandez’s 1651 natural history of Mexico, which also provided the literate world its first description of the North American coyote, described and even provided an initial illustration of the western pronghorn. But as was the fate of so many natural history descriptions in the period before the eighteenth-century Swedish naturalist Carolus Linnaeus codified science with his binomial classification system, pronghorns—like the other charismatic animals from the American West—did not come to the official notice of the Enlightenment Age until the Lewis and Clark expedition. While President Jefferson’s naturalist on the Red River, Dr. Custis, only heard reports of “a species of Antilope,” fellow explorers Meriwether Lewis and William Clark had direct experiences with pronghorns and, critically, collected a type specimen that they shipped to the East in 1805.

About the time Custis was writing Jefferson to tell the president he had heard stories of “Antilope” in the West, in Philadelphia Charles Willson Peale was unpacking Lewis’s specimen and preparing a mount for it. The Lewis and Clark party had seen their first pronghorns on September 5, 1804, not far from today’s Niobrara, Nebraska, during the same two-week stretch when they crossed that magical boundary from woodlands to prairies and first encountered (and began collecting) a whole suite of Great Plains animals: bison, prairie dogs, coyotes, mule deer, and magpies among them. A pronghorn buck’s turn came on September 14 when William Clark, fruitlessly searching for a volcano that was supposed to be in the vicinity, shot what he called “a (Buck) Goat which is peculiar to this Countrey. . . . verry actively made . . . his Norstral large, his eyes like a Sheep—he is more like the Antilope or Gazella of Africa than any other Species of Goat.”

Finding “Antilopes . . . feeding in every direction as far as the eye of the observer can reach” but discovering them to be “extreemly shye and watchfull,” Meriwether Lewis a few days later would pen a classic line about pronghorns. Hoping to collect a female for science, Lewis had the buck harem of seven he was stalking whirl away and disappear. Within minutes he spotted them more than three miles distant. “I had this day an opportunity of witnessing the agility and superior fleetness of this animal which was to me really astonishing,” he wrote in his journal. “When I beheld the rapidity of their flight along the ridge before me it appeared reather the rappid flight of birds than the motion of quadrupeds.”

Lewis and Clark would go on to make more than 200 pronghorn entries in their journals of their exploration, although they found them—like elk and deer—far less numerous west of the Continental Divide than on the Great Plains east of the Rockies. This was a phenomenon that appears to have had something to do with the relatively large population of Indians west of the mountains, and the fact that much of the Northern Plains from the Mandan villages westward was in the early nineteenth century a zone of warring tribes, which kept extensive hunting rare and allowed an unusual buildup of wildlife.

It was not so much “discovery” of the pronghorn by Lewis and Clark as their collection of a specimen they sent to eastern scientists that finally brought this several-million-year-old animal to the attention of modern scientific classification. It fell to George Ord, a Philadelphia naturalist and ornithologist who at the time was vice president of the Philadelphia Academy of Sciences and was working up many of the Lewis and Clark specimens from the West (among them the prairie dog and the grizzly) to publish a scientific description and propose a Linnaean name for the pronghorn in 1818. To his credit, Ord recognized that despite their similarities to African antelopes and gazelles, pronghorns were unrelated to any existing family of animals then known. Antilocapridae, the family name he devised, and Antilocapra, the genus Ord fashioned for a creature that seemed to combine the traits of both antelopes and goats, have stood ever since.

Surprisingly enough, although pronghorns came in for various mentions and notices, many western travelers in the nineteenth century had little additional information to add about pronghorns. That was a consequence in part of the pronghorn’s wildness and speed, which made it a difficult animal for many travelers to lay hands on, and also because—compared to more familiar animals like elk or deer—pronghorns were so unusual they were almost alien in the minds of many travelers. But there were some interesting takes.

When the failure of Jefferson’s Red River expedition brought Jeffersonian exploration to a close in 1806, Americans were almost fifteen years getting another scientific expedition into the West. But in 1819–1820 a party led by Stephen Long, which included naturalists Thomas Say and Edwin James and painter-illustrators Samuel Seymour and Titian Ramsay Peale, explored across the Central Plains from Iowa to the Front Range of the Rockies in present Colorado and New Mexico before returning eastward across the Southern Plains. Long’s party encountered pronghorns regularly and noted of them that “The antelope possesses an unconquerable inquisitiveness, of which the hunters often take advantage to compass the destruction of the animal.” Significantly, from his own animal drawings and a landscape sketch by Seymour, Peale completed a painting that became the American public’s first exposure to what pronghorns actually looked like in the wild. Peale’s painting was also one of the country’s first visuals of what an exotic place the American West could be.

The naturalists John Kirk Townsend and Thomas Nuttall, journeying across the plains with inventor/fur trader Nathaniel Wyeth’s party, on the Platte River on May 15, 1834, saw pronghorns for the first time and also gave the world an impression. Townsend wrote that the pronghorn “is one of the most beautiful animals I ever saw. . . . The legs are remarkably light and beautifully formed, and as it bounds over the plain, it seems scarcely to touch the ground, so exceedingly light and agile are its motions. This animal . . . inhabits the western prairies of North America exclusively.”

John James Audubon, with The Birds of America under his belt to rave reviews both in America and Europe, was on the Missouri River in 1843 attempting to add western animals to the book he was then working up on the mammals of North America. Audubon’s initial encounter to secure a pronghorn specimen to paint didn’t quite work out. He lured “a superb male” pronghorn from 300 yards out to less than 60 yards by taking advantage of its curiosity: “I lay on my back and threw my legs up, kicking first one and then the other foot, and sure enough the Antelope walked towards us.” His shot missed, however. Before finally completing another of the early visual representations of the pronghorn, Audubon noted that they “often die from the severity of the winter weather” and were “caught in pens in the manner of Buffaloes, and are dispatched with clubs” by Indian women.

One of the best-selling books of the West in the nineteenth century was the trader/naturalist Josiah Gregg’s Commerce of the Prairies, first published in 1846. It included sections on the wildlife of the Great Plains that often served up critical information on them. This is what Greg had to say about the pronghorn: “That species of gazelle known as the antelope is very numerous upon the high plains. This beautiful animal . . . is most remarkable for its fleetness: not bounding like the deer, but skimming over the ground as though upon skates. . . . The flesh of the antelope is . . . but little esteemed: consequently, no great efforts are made to take them. Being as wild as fleet, the hunting of them is very difficult.”

The commercial market hunt of wildlife in the West, initiated by the fur and robe trade, got under way on the Great Plains in earnest in the 1820s, but for almost three-quarters of a century—as long as beaver lasted, bison roamed in numbers enough to produce robes, hides, and tongues, and wolves and coyotes still were targets of traps and poison bait—it left pronghorns largely alone. Unlucky ones of course got shot by emigrants on the western trails, or were gunned down by foreign hunters on safari in the American Serengeti, or killed to provide food for railroad workers. By the 1850s and 1860s pronghorns were reaping the whirlwind in mining areas like California, where market hunters corralled and killed them to feed miners. But it was not until bison numbers began to drop, first on the Central and Southern Plains in the 1870s, then on the Northern Plains in the 1880s, that pronghorns finally began to attract attention in the slaughter of Great Plains animals for profit.

With more than 5,000 professional hunters in the West in the 1870s and 1880s, and Indians all across the plains not only invested in the market hunt but attempting just to stay alive on their new reservations, when every last buffalo had been pursued to ground, hunters looked to see what they might turn their guns on for a final killing spree. Without the bison herds as prey, wolves were going fast. Bighorn sheep in the Badlands lasted only a handful of years. Elk and even deer had mostly fled the plains to the safety of the mountains. In the 1880s only two primary charismatic animals remained on the Great Plains: wild horses and pronghorns. The horses would end up caught by mustangers and sold to overseas buyers whenever Europeans were involved in wars, or by the 1920s get rounded up as a source of dog food in the American pet industry. Or they were simply shot down by cowboys as nuisances. But pronghorns? They had evolved on the Great Plains, survived fearsome predators, lived through the Pleistocene extinctions. Erasing them from America was going to require some effort.

Naturally we were up to the task. As with the extinctions and close calls for so many birds and animals during this free-wheeling period of American history, there were multiple causes for what began to happen to pronghorns. Homesteading in places like western Kansas and Nebraska steadily tore up the prairie, and with it pronghorn habitat. Ranchers overstocked the plains with cattle and sheep that undermined vegetation pronghorns depended on. Those causes weakened pronghorns, but there were others that killed them directly, and in vast numbers. The new barbed-wire fences demarcating a West that was fast becoming private property went straight to the pronghorns’ evolutionary weakness. Fences that were loose or partly down they could wriggle through, but tight fences captured them, preventing the herds from migrating and from escaping winter blizzards. Without bison to tromp down the snow, in winter pronghorns couldn’t get at the plants they ate. Add fences to block their migrations and the horrific western winters of the 1880s devastated them. In an event that had become all too common, homesteaders in the Texas Panhandle discovered and killed 1,500 pronghorns trapped against a fence in the winter of 1882.

Then there was the market hunt. The generally poor opinion of pronghorn leather and their slight amount of meat had long kept pronghorns out of the rifle sights of men who killed animals for money. But with everything else gone and a deathly silence beginning to fall across the Great Plains, market hunters finally turned their rifles on pronghorns. The story is too familiar: sporadic but relentless and remorseless rifle fire echoed across a western landscape gradually emptying of animal life from the 1870s into the 1890s, and what had once been millions of wild creatures fell for a pittance in returns.

With bison dwindling and hunters looking for targets, winter concentrations of pronghorns around places like the Black Hills got wiped out in two or three seasons. A single hunter in California killed 5,000 for their hides when a drought drove pronghorns there to a few remaining waterholes. Hunters desperate to keep their lifestyle going sold pronghorn meat to butchers in Kansas for 2–3 cents a pound. In 1873 an Iowa firm shipped some 32,000 pronghorn and deer skins via railroad from the plains, barely selling them for more than $1 apiece for all that effort of hunting, skinning, and shipping. As always, the arrival of railroads to ship animal products coincided with a rising crescendo of gunfire, which happened when the Union Pacific reached Wyoming, the Santa Fe line reached New Mexico, and the Texas and Pacific became a market source that funneled pronghorn meat and hides from the Llano Estacado and all of West Texas.

When George Bird Grinnell alerted conservationist and future president Teddy Roosevelt to the impact of market hunting, a step that would eventually lead to the formation of the Boone & Crockett Club to protect American game animals, one of the victims he mentioned was the pronghorn. That had put pronghorns before an influential group, but by the time Roosevelt had become president, pronghorn numbers had dropped frighteningly low, to an estimated 13,000 remaining animals out of what had once been at least 15 million across the entire West. Rescuing them from almost certain extinction required, initially, cooperation between the states in the West, which Roosevelt facilitated, along with pronghorn stocking in Yellowstone, on the national wildlife refuges that TR created, and eventually on the scattering of national and state parks on the Great Plains. Real efforts occurred primarily between 1925 and 1945 and were commonly small-scale and regional, often spearheaded by state or provincial game departments, to use existing pronghorns to recover the animals in places where they had disappeared.

Pronghorns on the High Plains of New Mexico in 2015. Fifteen million pronghorns had plummeted to barely thirteen thousand a century ago. Dan Flores photo.

Every western state has a version of this story, but one example is Texas, which for millions of years absolutely swarmed with pronghorns. Biologist Vernon Bailey, representing the Bureau of Biological Survey in the Southwest in the years before it evolved largely into an anti-predator agency, crossed the Texas Panhandle by train in 1899. In the 100 miles between Canyon, Texas, and Portales, New Mexico, traversing premier antelope country across the Llano Estacado, Bailey counted only 32 pronghorns. Ten years before they had been fairly common in Trans-Pecos Texas; by 1899 they were all but gone there. It took a 1903 law against shooting them and expensive efforts to save pronghorns in Texas. By 1924 a census found only 2,407 in a state that had formerly held 20 percent of the continent’s pronghorn population. State efforts to restock them using a funnel net capture technique invented by the nearby New Mexico game and fish commission began in 1939. By 1944 there were 9,000 pronghorns in Texas, and by 1960 12,000. By the year 2000 the figure was 13,000, mostly in the Trans-Pecos and the Panhandle, better than none, certainly, but a faint echo of the millions that once were found in the region. Other states, particularly Wyoming and Montana, have fared better, and the US and Canadian population of pronghorns today hovers around 700,000 animals, half of them in Wyoming, with another 1,200 in Mexico. A series of highway overpasses now allows some of them to continue their winter migrations.

But I am still transfixed by a moment, for a few years in the 1880s and 1890s, when the two ancient Americans, pronghorns and mustangs, had still held out, finding themselves—along with coyotes—almost alone on the vastness of the American prairies. In April 1884 a cowboy named George Wolfforth, rounding up strays for the Kidwell Ranch in West Texas’s Yellow House Canyon, rode his horse up over the rim of the canyon about where Lubbock now stands. The scene he saw seared itself into his memory. “As far as we could see,” he wrote, “there were antelope and mustangs grazing in the waving sea of grass,” the whole tableau “rendered misty and unreal by the mirage that hovered over the plains.”

They were almost the sole survivors of the Pleistocene megafauna of the Great Plains. Many of their compatriots had died out in that mystifying extinction crash 10,000 years before, and almost all the rest had suffered extinction or extirpation across the previous 30 years. Here the two survivors still were in 1884. But even that moment was brief, soon enough was nothing but a romantic vision set down in a memoir. Those last herds extending as far as the eye could see proved as fleeting as Wolfforth’s mirage.