The question of whether wild horses are endangered is complicated because the term “wild horse” describes two distinct groups with entirely different conservation statuses. Most horses roaming free in North America and Australia are feral, descended from domesticated stock, not truly wild animals in the biological sense. This distinction creates conflict in management and public perception. The conservation status of truly wild species is one of fragile recovery, while feral populations face high numbers and intense management controversy.
The Status of Truly Wild Horses
The only remaining horse species considered truly wild, never having been domesticated, is the Przewalski’s Horse (Equus ferus przewalskii), often called the takhi. Native to the steppes of Central Asia, this species faced a severe population decline due to habitat loss and hunting pressure. By the late 1960s, the species was declared extinct in the wild, surviving only in zoos and captive breeding programs.
A successful international conservation effort began in the 1990s to reintroduce the takhi into native habitats in Mongolia and China. The species’ conservation status improved dramatically due to these programs. The International Union for Conservation of Nature (IUCN) reclassified the horse from “Extinct in the Wild” to “Critically Endangered” in 2008. By 2011, the status was downgraded again to “Endangered,” indicating the species still faces a high risk of extinction.
Feral Horse Populations and Management Status
The vast majority of free-roaming horses that generate public debate, such as the American Mustang and the Australian Brumby, are feral populations, not truly wild animals. Feral horses are domesticated species (Equus caballus) that have returned to a wild state. Unlike the endangered Przewalski’s Horse, these feral populations are not facing extinction; their numbers are very high and often exceed the sustainable capacity of their habitat.
In the United States, the Bureau of Land Management (BLM) manages American Mustangs and burros across 10 western states. The BLM establishes an Appropriate Management Level (AML), which is the calculated number of animals the rangelands can support alongside native wildlife. The national AML goal is approximately 27,000 horses and burros. However, the estimated population on the range as of early 2024 was over 73,000, nearly three times the established AML.
The overpopulation forces the BLM to conduct “gathers,” or roundups, to remove excess animals. Consequently, the number of horses and burros held in off-range corrals and pastures (over 64,000) nearly equals the number on the range. The Australian Brumby population is estimated to be over 400,000 animals and is managed as an invasive pest species due to its impact on sensitive ecosystems. These feral populations are characterized by ecological overabundance, requiring continuous, costly, and controversial management.
Key Factors Driving Status Conflict
The conflict surrounding feral horse management stems from disputes over resource allocation and ecological impact on public lands. Feral horses compete directly with native grazing wildlife, such as elk, deer, and pronghorn, as well as with privately owned livestock for limited forage and water resources. Horses are hindgut fermenters, meaning they graze continuously and consume grasses down to the root crown, often leading to greater ecological damage than other grazers. This intensive grazing degrades riparian areas, increases soil erosion, and reduces habitat quality for native species, including endangered ones like the sage-grouse.
The methods used to control the populations are the central point of contention between government agencies, ranchers, and advocacy groups. The primary management tool is the removal of animals via helicopter roundups, which is expensive and often criticized as inhumane. An alternative method is the use of fertility control vaccines, such as Porcine Zona Pellucida (PZP), delivered via dart to slow the reproductive rate of mares.
While fertility control is supported as a humane, non-lethal measure, its application is challenging in large, remote herds. The need for repeat booster doses and the difficulty in darting every mare in a vast area mean that fertility control alone has not been able to stabilize the high population growth rates. This constant cycle of overpopulation, roundups, and holding facilities fuels the public perception that the horses are being mismanaged or are in peril, even though the overall feral population is robust and biologically secure.