America's Wild Horses and Burros:
                    Research for Management 

Census of the McCullough Peaks, Wyoming Herd Management Area (HMA).

Tools necessary for treating   wild horse mares with PZP,  a fertility control drug.

The U.S. Congress passed The Wild Free-Roaming Horses and Burros Act of 1971 (Act) to protect, manage, and control wild horses and burros

Preparing equipment for aerial censusing.

on the public rangelands. The Act declared wild horses and burros as "living symbols of the historic and pioneer spirit of the West." It gave the Department of the Interior's Bureau of Land Management (BLM) and the United States Department of Agriculture's Forest Service the responsibility for wild horse and burro management and directed the agencies to manage these animals in a "thriving natural ecological balance." 

Largely unchecked by natural predators, many wild horse and burro populations grow at rates of 18–25 percent per year. This unregulated growth can result in unhealthy herds and unhealthy public rangelands. To ensure the sustainability and health of both wild horse and burro herds and the public lands, and to reduce the number of animals requiring either removal, adoption or long-term care in holding facilities, managers need alternative methods to control wild horse population growth and improved methods to estimate the number of mustangs and wild burros on the range.

The United States Geological Survey (USGS) at the Fort Collins Center is assisting the BLM by conducting research to study the effects of fertility control and develop more accurate methods to estimate wild horse and burro populations. For more information on these research projects, please visit the USGS website.

Administrating PZP.

A NV mustang in the Snowstorm HMA treated with PZP. Please note the identifying treatment mark on her hip.

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