In 1971 Congress passed the Wild and Free-Roaming Horse and Burro Act, designed to preserve a living symbol of America's frontier past. Thirty years later, there are fewer wild horses than ever.
One hundred years ago an estimated two million mustangs roamed the Western range. But today there are fewer than 50,000, according to the Bureau of Land Management (BLM). And the government has plans to reduce the herds even further—to just 27,000 by 2005.
Despite the statistics, America's wild horses are survivors. They've grown tough, living in harsh climates and unforgiving landscapes. With a high birth rate and few natural predators (hunting has thinned the ranks of mountain lions and bears) their numbers can climb fast. Too fast for the land to support them, says the BLM.
The BLM controls millions of acres of wilderness where most of America's wild horses are found. The agency, however, is responsible for maintaining the health of the land and it must strike a balance between the needs of ranching, recreation, and wildlife. In order to keep the mustang population in check, they hold periodic "gathers," rounding up "surplus" animals (the number of horses that exceed a pre-determined total for a particular area) for adoption.
Since 1971 nearly 159,000 horses have been gathered by the BLM. But a quarter of them never find homes. While the government has recently opened sanctuaries in Kansas and Oklahoma that can each take in 2,000 of the older "unadoptable" horses—horses that remain unclaimed after at least five auctions—there are, on average, 5,000 animals in BLM holding facilities at any given time.
"What to do with the animals that are removed from the range will always be a critical issue. It's unlikely even with aggressive advertising and promotion that we'll be able to find sufficient homes," said Linda Coates-Markle, who managed a BLM herd in the Pryor Mountains along the Wyoming and Montana border.
"Once the herds are down to what's known as appropriate management levels then the number of animals removed from the herd areas will balance the needs of the adoption program," she explained. "In order for that to work, the number of removals on an annual basis probably should not exceed 3,000 to 5,000. Right now we're removing closer to 8,000 to 10,000."
To meet that goal, herds have been radically reduced. But that in itself can present a problem. A herd needs at least 150 animals to maintain long-term genetic viability, according to Gus Cothran, an equine genetics specialist at the University of Kentucky. Yet 75 percent of the 209 herd areas managed by the BLM in the West have fewer than 150 horses.
One quick fix, suggested by Cothran, is to introduce a few carefully selected outsiders to the herd every decade or so. But Coates-Markle, working with the small herd in the Pryors, is researching other methods.
The Pryor Mustangs
The Pryor horses, descendents of Spanish horses brought to the New World by the conquistadors in the 16th century, are among the most intensely studied in the world. They found their way into North America from Mexico. And for the past 200 years, they have thrived in splendid isolation, surrounded on three sides by mountains and canyons.
With each generation (about ten years for horses), the Pryor horses have become more wild in spirit and primitive in form. They are smaller than their domestic counterparts, which is an advantage because a smaller body requires less fuel. Many also sport so-called primitive markings: a black stripe down their backs, striping across the withers, and zebra stripes on their legs.
As a small, genetically unique herd, living within a confined area accessible to researchers most of each year, the Pryor horses are ideal for study. Working with Colorado State University, Coates-Markle's team has developed ecosystem models to determine appropriate management levels. "We run different scenarios of weather and cycles of drought, basically trying to mimic environmental situations," she said. "And then we put in different levels of horses and see how the results vary in terms of overall health of the land."
Once an appropriate management level has been established—about 150 horses for the Pryor herd—the next task is selecting which horses should be removed at each roundup. It's a complicated process, taking into account an animal's age and sex, as well as status and genetic importance to the herd.
During the roundup this past September, yearling and two-year-old mares chosen to return to the wild were given primer shots for birth control. By delaying conception by a few years, it's hoped that mares will be in better shape to produce healthier foals. But it will also delay the need to hold gathers from once every three or four years, to once every seven or eight (see sidebar).
Some worry, however, about interfering with nature. "When humans start to select which mares will have foals when and where, then we are starting to enter the world of unnatural selection. And so we have to be very careful that we're doing it right and that we aren't going to create some difficulty down the road," said Ginger Kathrens of the Wild Horse and Burro Freedom Alliance.
Like all management tools, birth control alone isn't a magic solution. With less than 3 percent of the historic herd populations remaining, the problem may not be one of too many horses, but not enough land to support every use. "The West has been fenced in so ranchers can rotate their cattle on our public lands. And vast millions of dollars are spent every year to kill predators on public lands—mountain lions, bobcats, coyotes, bears—if they threaten livestock. We have to get the public lands back for the public. And in so doing, we'll give them back to the wild horses and all the wildlife that live here," said Kathrens.
The Pryor horses are lucky. Protected by geography and a team of dedicated researchers, they will be part of the landscape for decades to come. The glory days of the wild West may be a memory. But as long as there are wild horses kicking up their hoofs in freedom, the spirit of the frontier will never be completely lost to history.
By Janet Ginsburg
for National Geographic
No comments:
Post a Comment