Wild Horses and Burros

FORT researchers provide sound science to support the Department of Interior in its efforts to preserve American heritage, streamline species listing decisions and promote species recovery, manage wild horses and burros using efficient, cost-effective tools, and sustain hunting and fishing on public lands. This research is developed in partnership with resource managers from local, State, Federal...

The Wild Free-Roaming Horses and Burros Act of 1971, as amended, states that, "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 (PL 92-195, Sec. 1331, Congressional...

Researchers at USGS are using historical wild horse survey and monitoring records to conduct a study of horse density across sagebrush ecosystems of the western United States. Researchers will develop generalized density maps for the species that will enhance concurrent evaluations into the ecological effects of wild horse populations.

USGS researchers are conducting a comprehensive study of wild horse and livestock records across the greater sage-grouse range to investigate impacts on vegetation and wildlife (specifically, sage-grouse and songbirds). Researchers will use these results to evaluate Appropriate Management Levels for wild horse and burros, and projections of vegetation productivity under changing conditions.

Data from these studies help inform management decisions regarding ungulates on public lands, typically in large, jurisdictionally complex landscapes. Recent work involves investigations on the effects of herd size and movements of elk, bison, and wild horses on various ecosystem components. Specifically, scientific efforts include quantifying interactions among herbivores, plants, and soils...

Molecular tagging is a new application of molecular genetic techniques to traditional mark-recapture methodology designed to address situations where traditional methods fail. In such studies, non-invasively collected samples (such as feces, feathers, or fur) are used as a source of DNA that is then genotyped at multiple loci such that each individual animal can be uniquely identified. Thus, each...

Because population estimates drive nearly all management decisions pertaining to wild horses and burros, accuracy is important. Several widely used techniques exist for conducting aerial population estimates of wildlife, but individually, each has important limitations. Researchers at the U.S. Geological Survey, Fort Collins Science Center (FORT), are evaluating combinations of these techniques...

Wild horse populations often increase at high rates on U.S. western rangelands, which in turn can lead to habitat degradation. The U.S. Geological Survey and the Bureau of Land Management are cooperating on studies investigating the potential of fertility control drugs to reduce foaling rates. In addition, because nearly every management issue concerning wild horses depends on accurate herd counts...

The wild horses that roam the west are feral descendents of domestic animals that either escaped from or were intentionally released by early European explorers and later settlers. As a result of both origin and contemporary management, the Spanish or Iberian influence remains strong in some wild horse populations (e.g., the Kiger, Pryor Mountain, and Sulfur Mountain herds). In other populations...