Born to RunAn American Antelope in Texas

ARTICLE & PHOTOS BY MATT BUCKINGHAM

Two centuries past, when westward expansion began gripping our young nation, the American frontier was not defined by the towering mountains and rugged desert that exemplify the term today, but rather endless expanses of prairie inhabited by millions of American bison, pronghorn, elk, wolves, grizzly bears and diverse native cultures. As countless wagons wore ruts into the earth, black-tailed prairie dogs kept a watchful eye for badgers and black-footed ferrets, and a chorus of thriving grassland songbird populations filled the air. The majority of the Lone Star State was part of this magnificent expanse of grass. From the tallgrass prairies that lined the Gulf Coast to the Blackland and Cross Timber woodlands interspersed with meadows; and from the semi-arid grasslands of the Trans-Pecos to the Llano Estacado and the shortgrass prairies of the Panhandle Plains, Texas is a prairie state. And while the plains bison is perhaps the most well recognized symbol of the Great Plains and its plight, the pronghorn deserves a role right beside it as a true prairie icon.

Antilocapra americana, commonly known as the pronghorn, antelope, pronghorn antelope, speed goat, prairie antelope and other colloquial names, is one of North America’s most unique species. It is an animal that is at the same time beautiful, bizarre, graceful and gangly. They are supremely adapted for life on the prairie, and for speed and endurance. Adaptations like enlarged lungs, windpipes, and hearts, interlocking grooves in their joints that allow for a unilateral line of travel and an enhanced circulatory system make them the second fastest sprinters, and the fastest sustained runners on the planet. Other adaptations for life on the open plains include a pelage that is versatile with hairs that can draw in toward the skin to defend against the bitter cold of prairie winters, where air within their hollow structure adds additional insulation. Their hair can also stand erect to allow air to pass against the skin during the blistering heat of summer. Their eyes are huge, larger even than those of a horse, and afford them a field of vision greater than 300 degrees – an important trait to survey vast treeless expanses. And while they primarily perceive their world through their eyes, their sense of smell is keen as well, and it has been said by many a prairie old-timer that pronghorn can “smell” rain from many miles away, making significant movements to seek out water and fresh forage.

Their name originates from the pronghorn’s unique horns. They’re not quite antlers, which are carried by most members of the deer family (Cervidae), are comprised of solid cheetahs, which would have been a major predator of their habitats. Today there are no predators that can come close to matching an adult pronghorn’s speed or endurance in open country, and their enlarged eyes and exceptional field of vision allows them to spot a potential threat two miles away and ensure that a potential predator would rarely get the chance to test this theory.

The pronghorn’s conservation history begins like so many other species of American wildlife. When Europeans first visited the West, there were an estimated 35 million pronghorn roaming the plains. By the turn of the 20th century, it is estimated there were barely 10,000 left. That’s a population decline of over 99.999%. Like the American bison, the open country that the pronghorn called home made them easy targets for hunters. As the prairies became tamed by the hand of man, the conversion of native grassland to pasture and agriculture further impacted pronghorn populations. Texas was not spared the onslaught. There were historically two subspecies of pronghorn in Texas. Antilocapra americana americana, the common, or American pronghorn ranged across the Panhandle and Rolling Plains, Cross Timbers, Grand and Fort Worth Prairies, and into the Blacklands. Antilocapra americana mexicana, the Mexican, or Chihuahuan pronghorn occurred bone, and are typically shed each year. Nor are they quite like true horns, which are comprised of keratin, typically unbranched and carried throughout the year. Instead, they lie somewhere in between. The skulls of pronghorn bucks have bony protrusions that serve as the horns’ “cores.” Around them, pronged keratinous sheaths grow, and are shed each year. As with most deer, their headgear grows larger with age, though factors such as diet and genetics also play a role. The primary purpose of these horns is to communicate a male’s fitness to potential rivals and mates, and to engage in combat during the rut. It is believed by some that the “prong” is designed to catch a rivals horn and keep it from damaging the eye, as pronghorn depend so heavily on their supreme eyesight.

Despite commonly being referred to as antelope, pronghorn are not closely related to true antelope, which are restricted to the Old World. They are the only surviving member of the family Antilocapridae, a once diverse group which evolved in North America during the Miocene. Early Antilocaprids included Merriamoceros, which had horns shaped like fans or palm fronds, Ilingoceros, which had spiral horns, and Tetrameryx and Hayoceros, which bore four horns instead of two. The pronghorn’s closest living relatives are not deer, antelope, or goats, but are giraffes and okapis. The pronghorn’s extreme speed and endurance is believed to have evolved as a defense against extinct American in the Trans-Pecos and South Texas, with a likely contact zone that included the Edwards Plateau and other portions of central Texas. According to Pronghorn: Portrait of the American Antelope by Gary Turbak, there are only subtle differences between the subspecies, which include horn color, skull measurements, and the generally smaller size of the Mexican subspecies.

Early accounts note that pronghorn were encountered as far east as Falls and Milam counties. In 1845, in Narrative of an Expedition Across the Great Southwestern Prairies, from Texas to Santa Fé, pioneer and journalist George Wilkins Kendall described pronghorn as being common on the Upper Brazos. George Bernard Erath, another 19th century pioneer and early Texas politician noted pronghorn were also abundant in McLennan County, near his Waco home. In Texas with Particular Reference to German Immigration and the Physical Appearance of the Country, published by German born geologist and naturalist Ferdinand von Roemer in 1849, Roemer states that he observed pronghorn in the region where the Blackland Prairies meet the Lampasas Cut Plain. As the herds began to disappear, the pronghorn of South Texas held on a little longer than most other portions of the state. In their landmark 1905 work, Biological Survey of Texas, Vernon Bailey and Clinton Hart Merriam recount reports from early Anglo Texans that paint a picture of what once was. They provide an account from 1854 where

historian John Russell Bartlett describes seeing “thousands of deer and antelope” scattered about the prairie between Rio Grande City and Corpus Christi. At the turn of the twentieth century a few remnant herds were spotted in south Texas around the towns of Alice and San Diego, but as European settlement worked its way across the states, populations were diminished until a few scattered herds remained in the Panhandle and the Trans Pecos. A state population that was once estimated to contain a million individuals or more dwindled to only a couple of thousand by the time Bailey and Merriam published their biological survey in the early 1900s.

Fortunately, in the early 1900s efforts began to protect and restore both the species and its habitat. In Texas a temporary ban on hunting was enacted in 1903 to allow populations to recover. Restocking efforts in Texas began as early as 1939. Animals from nuisance and surplus populations from Texas, Colorado and Wyoming were released in an effort to repopulate the historic range of pronghorn in Texas. Between 1939 and 1982, nearly 6,000 individuals were transplanted.

in 1924 to over 17,000. At the time, West Texas contained the majority of the state’s population. What followed were 20 years of population fluctuations, until by 2008 just a few thousand individuals remained in the Trans-Pecos. A variety of factors were cited as possible causes. A significant drought in the late 1990s caused a dip, followed by a gradual increase until extended drought and a late season hard freeze in 2008 dipped the regional population to near record lows. This was followed by two years of very low fawn production. The stress from these events may have made the pronghorn more susceptible to parasites such as barber’s pole worms (Haemonchus spp.), which affect the stomach.

A 2009 study found that animals in the Trans-Pecos had higher occurrence of these worms than herds elsewhere.

Recognizing the dire situation, Texas Parks & Wildlife Department (TPWD) enacted a plan to capture 200 animals from the Panhandle, where populations have been increasing in recent decades, and translocate them to the Trans-Pecos. They put their plan into action in 2011, unaware that a

Populations in the Panhandle and Trans-Pecos gradually began to recover and in October 1944 a hunting season was held. It opened with some fanfare as the then Governor Coke Stevenson took a buck at a ranch near Alpine. It was the first of nearly 300 animals that would be taken in what was largely considered a huge success.

Following that fateful October day in 1944, pronghorn populations in Texas steadily continued to recover. By 1987, the Trans-Pecos herd recovered from a low of 692 animals historic drought loomed just around the corner. Nearly 80 percent of radio-tracked animals that were released perished. Undeterred, TPWD resumed translocation efforts in 2013 once the drought eased, and since that date have released hundreds of Panhandle pronghorn in the TransPecos. Though these efforts have helped gradually increase numbers in West Texas, the population remains tenuous. Of the approximately 20,500 pronghorn estimated to occur as of 2020, roughly 4,500 reside in the Trans-Pecos.

Translocation efforts can help increase genetic diversity within a population. This certainly has its benefits, however it can also dilute distinctive gene pools. In the case of TransPecos pronghorn, it is likely that few, if any pure Mexican pronghorn, remain, as translocated Panhandle animals introduced genes from the American subspecies into the population. In Pronghorn: Portrait of the American Antelope, published in 1995, author Gary Turbak suggests that a small genetically pure population of Mexican pronghorn remained near the town of Marathon. Since that time, numerous Panhandle animals were introduced to the Marathon Basin, and this herd is likely no longer purely comprised of Mexican pronghorn genetics. This can lead to an interesting debate – sacrifice the occurrence of the subspecies in the state, or risk losing pronghorn from the Trans-Pecos. This conundrum is not unique to pronghorn in Texas and is often brought up when wildlife reintroductions are discussed. At the end of the day, making every effort to ensure that this prairie icon remains in our west Texas prairies won out, and that’s probably for the best.

The main contemporary threat to pronghorn across Texas is a synergy of factors that reduces the pronghorn’s ability to tolerate certain environmental factors. Studies have shown that roads and fences form barriers to movement. This may create barriers to gene flow which could reduce the genetic diversity at a regional scale. These barriers may also prevent pronghorn from seeking out important food and water resources during periods of extreme drought. Where in unrestricted conditions, a pronghorn might travel up to 100 miles or more to find water or suitable forage, these barriers restrict their room to roam to what’s available on their side of the fence, so to speak. Fences may also make adult pronghorn more susceptible to predators, and there are reports of individuals being cornered by coyotes at 90-degree angles in fencelines. Research into the effects of barriers like roads is ongoing, but the presence of barriers no doubt contributed to the Trans-Pecos declines of the 2000s.

Today efforts are being made to address the impacts of these barriers. Groups like TPWD, Borderlands Research Institute, and the Texas Department of Transportation are working on the science to potentially implement wildlife crossings in areas with large pronghorn populations. Additionally, TPWD and various conservation organizations also work with private and public landowners to improve the landscape for pronghorn. They have worked to make hundreds of miles of Texas fence lines “pronghorn friendly,” connecting hundreds of thousands of acres of pronghorn habitat. Pronghorn famously avoid jumping over fences, but do not hesitate to crawl under them. Unfortunately, many traditional wire fences have bottom wires that are too low to allow pronghorn movement, and are adorned with sharp barbs. According to TPWD’s A Landowner’s Guide to Pronghorn-friendly Fences, landowners can improve their fences by raising the bottom wire or net-wire to a minimum of 18 inches off the ground for at least 20 yards for every half mile of fence, replacing bottom strands of barbed-wire fence with smooth wire, modifying corners to allow escape routes for pronghorn that might be cornered by predators, and remove any old or unused fence segments, including posts and stays. Better yet, if possible, landowners should remove their fences to allow these icons to roam unimpeded as they did for millennia prior the arrival of European settlers.

Nationwide, pronghorn populations have recovered from around 15,000 individuals in 1915 to an estimated one million plus today. Regulated hunting seasons, reintroduction efforts and habitat enhancement has fueled a tremendous recovery, though there are still many portions of their historic range that can no longer support healthy pronghorn populations.

Pronghorn strongholds in Texas today include the semiarid grasslands of the Trans-Pecos, including the Marfa and Marathon grasslands. They can readily be seen around the towns of Alpine, Fort Davis and Valentine, and in the prairies between the Guadalupe Mountains and El Paso. They are common in many areas of the Panhandle, with the Rita Blanca National Grasslands and the vicinity of the community of Pampa being good places to glimpse one. There are also small herds south of Midland/Odessa, and between Big Lake and San Angelo.

Like the American bison, America’s “antelope” is a prairie icon that has come back from the brink. The populations of the Trans-Pecos of Texas, however, continue to face obstacles to recovery. If you are a landowner, or know a landowner in pronghorn country, please consider ensuring that your fencelines are “pronghorn friendly” so that this special hooved Texan can roam the plains unimpeded once more.