Wild Horse and Burro Overpopulation

Elise Thompson

MAY. 3, 2021

Overpopulation of wild horses and burros in the West is a very prevalent issue, that for the most part remains considerably under-recognized, misunderstood, and oftentimes even unheard of.

Overpopulation of wild horses and burros in the West is a very prevalent issue, that for the most part remains considerably under-recognized, misunderstood, and oftentimes even unheard of.
The issue was first addressed on December 15, 1971, when the Wild and Free-Roaming Horses and Burros Act was signed into law by the president at the time, Richard M. Nixon. This newly established act put all wild horses and burros on public lands under the control of the Bureau of Land Management (BLM), alongside the US Forest Service. The purpose of this act was to protect these wild herds, but also to maintain and preserve the grasslands that they live on for years to come. However, maintaining this ecological balance is something that the BLM has struggled with ever since the act’s establishment. The Wild and Free-Roaming Horses and Burros Act of 1971 states that these herds “contribute to the diversity of life forms within the Nation and enrich the lives of the American people.” Despite this, much of the public is blissfully unaware of the overpopulation conditions these glorified animals are subject to. While we may envision herds, galloping carefree, across the grasslands of the West, the stark reality is that they may soon be lost. After years of struggling with overpopulation and environmental deterioration, it has now become clear that unless a new herd management strategy is formulated and acted upon, the future of the nation’s wild horses and burros could be devastating.
The nation’s wild horses and burros descended from domesticated animals that were brought over to the Americas in the 15th and 16th centuries by the Europeans. Since then, their population grew largely in numbers to greatly populate the rangeland in the West, primarily in ten western states with more than half the population in Nevada. Fifty years ago, in 1971 when the BLM and the US Forest Service initially surveyed the number of wild horses and burros, there was only a total of 25,345. Since then the number has skyrocketed to almost four times the original survey amount to around 95,000 and continues to grow by about twenty percent every year.
This overpopulation greatly exceeds the Appropriate Management Level, also known as the AML, of 26,690 wild horses and burros. The AML was established to determine how many animals the land can sustain to create a thriving ecosystem without deteriorating the rangeland. However managing the AML of wild horses and burros is a much different task than managing the AML of any other species, where a combination of hunting and natural predators keep populations in check. Horses and burros on the other hand are protected from hunting and they lack an abundance of natural predators. As a result, the number of horses and burros is much higher than the carrying capacity of the land. Herds oftentimes have to travel over 20 miles a day between their limited forage and water supply. With an overwhelming amount of animals densely populating the land, ground and soil is being torn up thus leading to long-lasting damage seen through a lack of fertilization and low levels of water absorption. Overgrazing also occurs and forces horses and burros to compete with other livestock and native species for grazing ground. All these factors combined are leading to great starvation, and a continually rising population; two separate problems that combined have created a major ecological issue.
To combat this rising population and environmental destruction, the BLM has implemented strategies in an attempt to manage herd sizes. The BLM regulates herd sizes on 26.8 million acres of land, however, in doing so they have come across major problems. There are simply too many animals living off the land, so the BLM systematically gathers burros and mustangs into temporary holding pens. From there the animals are provided food, water, veterinary care and are put up for sale or adoption. When short-term hold-pens fill up, the horses and burros that are deemed very unlikely to be adopted are moved to long-term holding pastures. Currently, both short-term and long-term holding pens are filled nearly to capacity with 47,845 animals in off-range holding areas. The majority of the BLM’s budget is spent just providing for and caring for all these animals in holding. Maintaining these off-range herds costs taxpayers about $50 million each year, which is more than half BLM’s budget. On top of the growing population, limited natural resources, and crowded holding pens, the adoption rate of these horses and burros is unfortunately low. In fact, it has been slightly decreasing with an excess number of animals still in holding. The adoption market is extremely difficult, due to the wild, feral, and untrained nature of the horses and burros.
While this overpopulation management issue may seem simple on the surface, many people across the United States have found it to be an issue of great controversy, and it is associated with many un-backed myths. In order to move forward, it is critical that science and facts stand as an educational foundation to gain trust from the public.
It is important to recognize that everyone is moving towards one common goal of maintaining public lands for generations to come. The future for these wild horses and burros is bleak without changing long-term management strategies. If no action is taken, the classic “boom-and-bust cycle” seen throughout history will occur - the population will greatly increase, food will become scarce, and then through lack of resources, the population will dramatically decrease.
Interestingly enough, population management through the use of contraceptives is greatly underused. If the BLM could reduce the population level of wild horses and burros to a manageable base level through fertility control, growth could match adoption demand. Incentivising adoptions in combination with increased use of contraceptives, such as Porcine Zona Pellucida (PZP) and Gonacon, is the only publicly acceptable and sustainable method to maintain the AML possible. Educating the public, particularly the agricultural community, on this misunderstood and often unheard of overpopulation issue is also a must. Hopefully, in the future, we can move towards establishing sustainable herd management in order to reinstate wild horses and burros as a symbol of American success, rather than a reminder of the US’ failure to maintain ecological balance.