Wild Free Roaming Horse And Burro Management

Following passage of the Wild Free-Roaming Horses and Burros Act in 1971, limits for the number of horses on each herd unit (referred to as Herd Management Areas or HMA's) were set. These limits or population goals are referred to as Appropriate Management Levels or AMLs. From 1980 and through the present, more active management reduced wild horse numbers closer to AMLs. Wild horse numbers were reduced to about 40,000 by 1999 and to about 37,186 wild horses in 2003, prior to the foaling season. Some 203 HMAs are managed by the BLM across the Western U.S. The responsibility of monitoring range conditions; allocating range resources between horses, livestock, and wildlife; monitoring horse and burro numbers and managing their population levels represents a large federal management responsibility. The number of animals in most herds are counted or estimated every three to four years, in order to plan for any gathers, and adoptions. Herd management activities, such as gathers and removals, take place for most herd areas every four years.

Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward reviews the science that underpins the Bureau of Land Management's oversight of free-ranging horses and burros on federal public lands in the western United States, concluding that constructive changes could be implemented. The Wild Horse and Burro Program has not used scientifically rigorous methods to estimate the population sizes of horses and burros, to model the effects of management actions on the animals, or to assess the availability and use of forage on rangelands. Evidence suggests that horse populations are growing by 15 to 20 percent each year, a level that is unsustainable for maintaining healthy horse populations as well as healthy ecosystems. Promising fertility-control methods are available to help limit this population growth, however. In addition, science-based methods exist for improving population estimates, predicting the effects of management practices in order to maintain genetically diverse, healthy populations, and estimating the productivity of rangelands. Greater transparency in how science-based methods are used to inform management decisions may help increase public confidence in the Wild Horse and Burro Program.