Mustangs have been a part of the landscape of the United States for centuries. Ever since the first horses escaped from Spanish conquistadors, feral horses have returned to their wild roots, roaming in small family bands lead by stallions, mixing with various breeds of other escapees — including the Appaloosas and paints of Native Americans, ranchers' quarter horses and cow ponies, thoroughbreds, and draft horses that ditched their farms.

The mustang has become an exceptionally hardy breed of horse, adapting easily to rough and arid conditions in the west, with isolated bands still showing their centuries-old ancestry though particular conformation and markings. And importantly, the mustang is a breed we equate with freedom, an untamed spirit, and the history of our country.

The Bureau of Land Management (BLM) is tasked to uphold the 1971 legislation written to protect these free-roaming horses, the Wild Free Roaming Horses and Burros Act. Unfortunately, the BLM's strategies are far from effective and are considered by many to be inhumane. The issue is complex and has many conflicting interests, from those who want to see wild horses stay free, to those who object to the strategies used for limiting herd growth, to ranchers who graze their livestock on public land and view the mustangs as competition.

mustangs run through western scrub habitatWild horses protected by the BLM are found primarily in Western states. (Photo: Jaymi Heimbuch)

Most recently, wild horses and the BLM made headlines in late July 2017 when a Congressional committee voted to reverse a ban on euthanizing healthy wild horses and burros.

“Let’s be clear: House Appropriations Committee members just signed a death warrant for America’s mustangs and it will lead to the wholesale destruction of these irreplaceable national treasures,” said Suzanne Roy, director of the American Wild Horse Campaign, in a news release.

If the amendment becomes law, the BLM would be permitted to kill animals deemed unadoptable that are being kept in holding pens or that are still roaming public lands.

“This request comes out of the desire to do well by the horses,” Jason Lutterman, a BLM spokesman, told The Denver Post, "The population of wild horses and burros continue to outstrip the resources available for them. It’s a growing problem on the range and BLM doesn’t have the tools to manage that population effectively.”

Obviously, the sides don't agree.

Here are some of the basics of the controversy surrounding one of the most iconic animals in the United States.

Mustangs by the numbers

mustangs stand on a hilltopMustangs stand on a hilltop. (Photo: Jaymi Heimbuch)

  • The mustang population is under strain. There are a record 67,000 wild horses on some 27 million acres of federally managed land, while millions of privately-owned cattle graze across some 155 million acres of public lands, including those acres designated for wild horses. (Note: This and all numbers below are based on 2014 figures.
  • Wild horses and burros can be found mainly on government-designated Herd Management Areas (HMA) in 10 western states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah and Wyoming.
  • BLM has reduced designated wild horse habitat by more than 15 million acres since 1971.

Livestock versus mustangs on public lands

mustangs on a sanctuaryMustangs in a sanctuary. (Photo: Jaymi Heimbuch)
  • The American mustang is outnumbered 35 to 1 by the privately owned livestock allowed to graze on public lands.
  • Livestock grazing on public lands costs taxpayers in excess of $122 million annually. The cattle grazed on public lands provide a mere 3 percent of the U.S. beef supply.
  • Cattle are more damaging to fragile riparian habitats than horses. Studies have shown wild horses roam much farther from water sources than cattle, which tend to graze within one mile of water sources, causing erosion, overgrazing, and contamination. However, public land fencing often prevents horses from accessing natural water sources and disrupts their natural widespread grazing patterns.
  • Mustangs are restricted to just 17 percent of BLM lands. Still, the BLM allocates the majority of forage resources in HMAs to private livestock instead of mustangs and burros.

The value of legal protection

captive mustangs run through a pasture togetherCaptive mustangs run through a pasture. (Photo: Jaymi Heimbuch)

  • Mustangs technically have legal protection. In 1971, Congress passed the Wild Free Roaming Horses and Burros Act, declaring "wild free-roaming horses and burros are living symbols of the historic and pioneer spirit of the West; that they contribute to the diversity of life forms within the Nation and enrich the lives of the American people; and that these horses and burros are fast disappearing from the American scene. It is the policy of Congress that wild free-roaming horses and burros shall be protected from capture, branding, harassment, or death; and to accomplish this they are to be considered in the area where presently found, as an integral part of the natural system of the public lands."
  • Population growth is not regulated by self-limiting pressures, such as lack of water or forage and presence of natural predators. Because of this, mustang populations grow at an annual rate of 15-20 percent.
  • Despite successful reproduction rates, the breed is still in danger because the BLM is taking so many wild horses out of HMAs. The BLM's target number for mustangs left in the wild is lower than the estimated population in 1971 when the act was passed.

Trauma of roundups and holding pens

mustangs rounded up by helicopter Mustangs are rounded up by helicopter. (Photo: Justin Sullivan/Getty Images)

  • Mustangs are often injured or die during or as a result of government roundups. Leg and hoof injuries from running over rough terrain, injuries from panicking in pens, dehydration and over-heating, spontaneous abortions by mares after the strenuous roundup, foals that collapse or are separated from their mothers in the commotion, stallions fighting after being forced into pens together, permanent mental trauma and other significant injuries are the result of "gathers".
  • Most mustangs rounded up don’t get adopted, as BLM reports show. Due to BLM's rounding up horses into long- and short-term holding facilities, there are more mustangs in government holding facilities than there are in the wild.

Budgetary breakdowns

mustangs lead into holding pens by helicopter Mustangs gallop into a holding pen, rounded up by a helicopter. (Photo: Justin Sullivan/Getty Images)

  • Long-term holding costs consume over half of the Wild Horse and Burro Program's annual budget. In fiscal year 2012, the BLM spent over $40 million to care for more than 45,000 mustangs removed from the range and put in holding.
  • The BLM focuses the majority of its budget on roundups, removal and warehousing of horses. In July 2017, there were 46,000 horses and burros being kept in holding facilities with the agency estimating it would cost $1 billion to care for the animals over their lifetime. .
  • Mustangs captured in government roundups have commonly ended up in slaughterhouses in Canada and Mexico after being sold. In 2013, new rules for mustang adoptions were put into place after an investigation discovered nearly 1,800 horses were sold to a livestock hauler who most likely sent the horses to slaughter. Now, no more than four mustangs can be adopted by an individual within a six-month period unless prior approval is obtained from the BLM.

Herd management flaws

mustang in scrub brushA mustang stands in scrub brush. (Photo: Jaymi Heimbuch)

  • After two years of review, the National Academy of Sciences (NAS) released a report that shows how the BLM’s management of wild herds is ineffective and unscientific, with suggestions for improvement.
  • The NAS report notes that the BLM does not use scientific methods for estimating the number of horses in an area, monitoring herds or calculating how many horses an area can reasonably sustain. The NAS supports herd management on the range as a more economically viable and ecologically sound approach to limiting wild horse populations.

Solutions for long-term success

mustangs move together at sunriseMustangs move at sunrise. (Photo: Jaymi Heimbuch)

There are solutions for humane long-term management, that would effectively end inhumane roundups and stop the flow of tax-payer money to keeping mustangs in holding pens. They include:

Self-stabilizing herds - Putting up natural boundaries where needed and allowing natural predators such as mountain lions to reenter the restored ecosystems. This self-regulating model has worked with the Montgomery Pass herd where this herd has survived and maintained a stable population for twenty-five years without human management.

Fertility control - A contraceptive vaccine called PZP, which is approved by the Humane Society of the United States, has been used successfully with the wild horses of Maryland’s Assateague Island. Administering it requires only remote darting of mares, which doesn’t disrupt the social structure of the wild bands. It could save taxpayers as much as $7.7 million annually.

Ecotourism - Free-ranging mustangs are a draw for American and international tourists alike. Building non-disruptive sight-seeing and tours to watch mustangs can bring income to the areas in which they roam and show they are more valuable alive than in holding pens or sent to slaughter.

Cooperation from ranchers - By working with ranchers who graze their livestock on public land, and requiring them to allow mustangs the same access to resources such as water as their livestock receive, The BLM could reach a balance between protecting the herds on Herd Management Land as the law requires and satisfying ranchers’ needs.

mustang runs over a hill in silhouetteA mustang races over a hill. (Photo: Jaymi Heimbuch)

Much of this information has been gathered from the American Wild Horse Preservation Campaign, a nonprofit organization that stays on top of the issue, keeping in touch and on the ground from Capitol Hill down to the ranges where mustangs are rounded up. It provides a good deal of information about the status of mustangs and what is, or rather, isn't being done to protect this iconic breed. It is a great resource for anyone interested in learning more.

Another excellent resource for learning exactly what is going on is the full report from the National Academy of Sciences, "Using Science to Improve the BLM Wild Horse and Burro Program." It is free to download and reveals from a scientific perspective where the BLM falls short of helping the very animals it is tasked to protect.

Editor's note: This story has been updated since it was originally published in January 2014.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.

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