Why and how do wild horses exist?

Q: Where can I find America’s last wild horses and burros?

A: Today, wild horses and burros can be found primarily on government-designated Herd Management Areas (HMAs) in ten western states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah and Wyoming. Six states have already lost their wild horse populations entirely.

Q: Are wild horses overpopulating and starving? 

A: No. The BLM and its friends, who want to legitimize the murder of our wild horses, say that wild horses are overrunning the West and starving to death. This is blatant propaganda. In fact, wild horses are present on just a tiny fraction of BLM land in the West and ranchers have access to livestock grazing on over 80 percent of BLM rangelands without any wild horses present. Except in a few rare occurrences during the past several years, wild horses in the West are healthy and prospering. This is shown by the fact that the great majority of horses and burros seized from public lands are in excellent physical condition. Wild horses and burros are not starving and the only thing overpopulating the West is the massive number of cattle and sheep that continue to degrade our public lands.

Q: Do wild horses cause overgrazing on public lands?

A: Livestock usage, not wild horses, is the primary driver of deterioration of public lands. Cows graze within a mile of water, while wild horses are highly mobile, grazing from five to ten miles from water, at higher elevations, on steeper slopes, and in more rugged terrain. The National Academy of Sciences discovered that cattle utilized 70% of grazing resources on public lands in one year, whereas wild horses and burros devoured less than 5%.

Q: Do wild horse herds really increase in size every five years?

A: In its 1982 study, the National Academy of Sciences found “annual rates of increase of 10% or less” in wild horse populations, a far cry from the 20% increase relied upon by the BLM to justify its removal program. Paradoxically, it is the BLM’s own management rules that are aggravating the issue in places with higher-than-normal population growth rates. • “Management techniques are promoting high rates of population expansion,” according to a 2013 National Academy of Sciences assessment. … Consequently, removals might boost population growth rates via compensating population expansion from reduced competition for feed. As a consequence, management is likely to increase the number of animals processed through holding facilities.’

Q. Do wild horses have any natural predators?

Mountain lions are the most common predators of wild horses. In 2004, for example, just one foal out of 28 survived in Montana’s Pryor Mountain region. Mountain lion predation was mostly responsible for the poor survival rate. Unfortunately, in many areas, predators that could help keep wild horse herds in check are eradicated via hunting and by government programs that kill predators for the benefit of ranchers.

Q: Aren’t wild horses a non-native species?

A: Wild horses are a natural animal species that has been reintroduced. Paleontological data indicates that wild horses developed on the North American continent over 1.6 million years. It’s unclear how they vanished 11 to 13 thousand years ago, or whether they ever went extinct here. When Cortez landed in Mexico in 1519, he brought horses from Spain. Others soon followed. These restored animals produced a large number of wild horses, which influenced Plains Indian civilization. The Spanish horses quickly adapted to the same ecological niche in which their original counterparts formerly flourished. They were here as a reintroduced, well adapted animal species, 3 million strong, long before the early immigrants pioneered the West. Please read our History Overview for additional details.

Q: But isn’t the contemporary horse species distinct from the one that went extinct so long ago?

A: The majority of those early diverging species were genetically identical. Modern molecular biology, using mitochondrial DNA analysis, has shown that the genetic equivalent of Equus caballus emerged, diverged as a species, about 1.6 million years ago, disappearing from the North American continent presumably 11 to 13 thousand years ago. Even more recent molecular study has shown that the modern horse might have diverged as recently as 300,000 years ago. Please see Wild Horses as Native North American Animals for a more in-depth look at these new discoveries.

Q: What distinguishes wild horses from domestic horses?

A: The American wild horse, the consequence of 500 years of natural selection, differs from domesticated horses in both morphology and behavior. Natural selection has preserved the hardy characteristics of the horses that shaped the American West: a 1998 Kansas State University study discovered that wild horses are far less prone to bone disease than domestic counterparts; wild horses also stand out for the remarkable hardness of their hooves. Moreover, a University of Kentucky research found that, despite intensive culling, wild horse populations are genetically significantly more diversified than any domestic horse breed. Some herds such as Utah’s Sulphur Spring herd are a direct link to the primitive Iberian horse and have been recognized by geneticists as a resource of “truly unique and irreplaceable genotypes, a zoological treasure.” Several characteristics of the endangered Sorraia breed are retained in these horses, including triple dorsal stripes, zebra striped legs, and chest barring.

Q: What about burros?

A: The position of wild burros is considerably more hazardous than that of their wild horse kin. Descendants of the burros used by miners as pack animals in the 1800s can still be found in Nevada, Arizona and California, where they share their habitat with bighorn sheep, a highly-prized game species that outnumbers them at least 16 to 1 on public lands. Under pressure from the hunting lobby, BLM consistently removes burros from their legally allocated range to increase the number of available bighorn hunting tags; BLM has set the population target for burros at less than 3,000 nationally. However, the National Park Service has a zero wild burro policy: burros discovered on its property are frequently slain in an eradication effort known as “direct reduction.” Please see our Burro website for additional information, and our Witness Reports page for an eyewitness description of a burro round-up.

Q: Why do wild horses have to be managed at all?

Today’s wild horses and burros live in situations that are far from natural. They are restricted inside Herd Management Areas, which establish artificial habitat borders and often block off the animals’ seasonal migratory paths. They live on land that is shared by multiple uses, including livestock grazing, and in areas where natural predators like mountain lions are eradicated by hunters and by a government program that kills predators for the benefit of ranchers. Under these conditions, some form of management is necessary, but the BLM’s roundup and removal approach is not only inhumane, but also it is completely unsustainable and  has brought the program to the brink of fiscal collapse.

Q: How should wild horses be managed?

The AWHC supports the use of the PZP immunocontraceptive vaccination on mares to limit population growth rates in a humane manner. The vaccination may be administered remotely through darting or by hand injection after horses have been humanely acquired using bait traps. When administered to pregnant mares, the vaccination induces an immunological response that inhibits fertilization and has no impact on fetuses. The PZP vaccination has no effect on the reproductive hormones that regulate natural behavior. It is reversible been proven safe, effective and humane over nearly three decades of use in numerous wildlife species, including wild horses.

Why not just geld the stallions and spay the mares?

Unlike the PZP vaccine, surgical sterilization woudl take the wild out of wild horses by destroying the wild free-roaming behaviors that distinguish wild horses from their domestic counterparts. “A potential disadvantage of both surgical and chemical castration is loss of testosterone and consequent reduction in or complete loss of male-type behaviors necessary for maintaining social organization, band integrity, and expression of a natural behavior repertoire,” the National Academy of Sciences concluded. In addition, it warned that spaying mares (surgically removing their ovaries) — a procedure that is rarely done in domestic mares — was dangerous: “Since ovariectomy may result in prolonged bleeding or peritoneal infection, it is not recommended for use in the field.”

Related Questions

• What is the purpose of a wild horse?

  Wild horses may serve as landscapers and lawnmowers, mowing away flammable grasses and weeds. Ecological value: Science exists to support that wild horses have many beneficial impacts on their environments and other science exists that wild horses have negative impacts on their environments.

• How did wild horses become wild?

  Millions of years ago, wild horses emerged and grew on the North American continent. As the sea level dropped during glacial times, they would traverse the Bering Land Bridge into Siberia. Horses became extinct locally 12,000 years ago, yet they were not globally extinct.

• Are there any truly wild horses left?

  The takhi is the world’s last truly wild horse. The so-called “wild” horses that abound in Australia and North America are actually feral.

• Why are there so many wild horses?

  They are derived from domestic horses that Europeans imported to the continent beginning in the 16th century. “All of the horses are feral—they were released,” says Terry Messmer, a professor in the department of wildland resources at Utah State University. “They arrived in an ecology with which they did not co-evolve.”