Wild Horse and Burro Quick Facts
Contact: Tom Gorey, BLM Public Affairs (202-912-7420)
Updated as of March 28, 2014
Wild Horse and Burro Population
The Bureau of Land Management estimates that 40,605 wild horses and burros (about 33,780 horses and 6,825 burros) are roaming on BLM-managed rangelands in 10 Western states, based on the latest data available, compiled as of February 28, 2013. Wild horses and burros have virtually no natural predators and their herd sizes can double about every four years. As a result, the agency must remove thousands of animals from the range each year to control herd sizes.
The estimated current free-roaming population exceeds by nearly 14,000 the number that the BLM has determined can exist in balance with other public rangeland resources and uses. The maximum appropriate management level (AML) is approximately 26,677.
Off the range, as of March 2014, there were 48,812 other wild horses and burros fed and cared for at short-term corrals and long-term pastures. (Specifically, there were 14,595 horses and 1,112 burros in corrals [for a total of 15,707 animals in short-term holding] and 33,105 horses in pastures. The combined figure of 48,812 animals in holding compares to the BLM's total holding capacity of 52,083.) All wild horses and burros in holding, like those roaming Western public rangelands, are protected by the BLM under the 1971 Wild Free-Roaming Horses and Burros Act.
Wild Horse and Burro Acreage
In 1971, when Congress passed the Wild Free-Roaming Horses and Burros Act, these animals were found roaming across 53.8 million acres known as Herd Areas, of which 42.4 million acres were under the BLM's jurisdiction. Today the BLM manages wild horses and burros in 179 subsets of these Herd Areas (known as Herd Management Areas) that comprise 31.6 million acres, of which 26.9 million acres are under BLM management. For the answer to the question "What happened to the 'missing' 22.2 million acres on which wild horses and burros were found roaming?," see below. Also, it should be noted that under the 1971 Act, horses and burros may not be re-located to other public lands where they were not found roaming when the law was passed.
Wild Horse and Burro Budget
Congress appropriated $71.8 million to the Wild Horse and Burro Program in Fiscal Year 2013, which ended September 30, 2013. Of the enacted appropriations ($71.8 million), holding costs accounted for $46.2 million (64 percent). Of that year's expenditures ($76.1 million), gathers and removals cost $4.8 million (6 percent), and adoption events cost $7.5 million (10 percent). (The $4.3 million difference between appropriations and expenditures is the result of the use of "carryover" and prior-year, contract-related funding.)
Removing Wild Horses and Burros from the Range and Placing Animals in Adoption
To help ensure that herd sizes are in balance with other public rangeland resources and uses, the BLM removed 4,176 (4,064 horses and 112 burros) from the range in Fiscal Year 2013, which ended September 30, 2013. (This figure compares to 8,255 animals removed from the range in FY 2012.) The Bureau placed 2,671 removed animals into private care through adoption in FY 2013 -- less than half as many as a decade ago (5,701 were adopted out in FY 2005). Since 1971, when Congress passed the Wild Free-Roaming Horses and Burros Act, the BLM has adopted out more than 230,000 horses and burros. For more information about adoptions, please visit How to Adopt and the national adoption schedule.
Population Growth-Suppression Treatments
In Fiscal Year 2013, the BLM applied 509 fertility-control treatments to mares, 310 with PZP-22 and 199 with PZP (porcine zona pellucida, now known as ZonaStat H).
In FY 2012, the BLM applied 1,051 PZP fertility-control treatments to mares and released 180 more stallions than mares back into herds during gather operations, for a grand total of 1,195 population growth-suppression treatments in FY 2012.
With regard to a call by advocacy groups for a moratorium on all BLM gathers of herds, this is untenable given the fact that herds grow at an average rate of 20 percent a year and can double in size every four years.*
* Eberhardt, L. L., Majorowicz, A. K. & Wilcox, J. A. (1982). Apparent Rates of Increase for Two Feral Horse Herds. The Journal of Wildlife Management, 46(2), 367-374.
Garrott, Robert A., Siniff, Donald B. & Eberhardt, L. Lee. (1991). Growth Rates of Feral Horse Populations. The Journal of Wildlife Management, 55(4), 641-648.
Garrott, Robert A. & Taylor, Lynne. (1990). Dynamics of a Feral Horse Population in Montana. The Journal of Wildlife Management, 54(4), 603-612.
The ecosystems of public rangelands are not able to withstand the impacts from overpopulated herds, which include soil erosion, sedimentation of streams, and damage to wildlife habitat. As for the 1971 Wild Free-Roaming Horses and Burros Act, Section 1333 of that law mandates that once the Interior Secretary "determines...on the basis of all information currently available to him, that an overpopulation exists on a given area of the public lands and that action is necessary to remove excess animals, he shall immediately remove excess animals from the range so as to achieve appropriate management levels."
About 8,400 wild horses and burros immediately became eligible for sale under the December 2004 sale-authority law (the so-called "Burns Amendment"), which directs the BLM to sell "without limitation" to any willing buyers animals that are either more than 10 years old or have been passed over for adoption at least three times. Since 2005, the Bureau has sold more than 5,500 horses and burros. It has been and remains the policy of the BLM, despite the unrestricted sales authority of the Burns Amendment, not to sell or send any wild horses or burros to slaughterhouses or to "kill buyers."
The proceeds from the sale of the eligible animals are used for the BLM’s wild horse and burro adoption program, as directed by Congress under the sale-authority law.
BLM’s Legal Mandates
The BLM manages the nation’s public lands for multiple uses, in accordance with the 1976 Federal Land Policy and Management Act. The Bureau manages wild horses and burros as part of this multiple-use mandate.
The BLM manages, protects, and controls wild horses and burros under the authority of the 1971 Wild Free-Roaming Horses and Burros Act (as amended by Congress in 1976, 1978, 1996, and 2004). This law authorizes the BLM to remove excess wild horses and burros from the range to sustain the health and productivity of the public lands.
In enforcing the 1971 Act, the BLM continues to work with law-enforcement authorities in the investigation and prosecution of those who violate this landmark law. The text of the law can be accessed here.