Congress passed The Wild Free-Roaming Horses and Burros Act of 1971 with the intent of protecting and controlling wild horses (and burros). They reasoned that these critters were “living symbols” of the past of this nation.  Congress appointed the U.S. Bureau of Land Management, among others, the responsibility of managing the wild horses and burros to give them a “thriving natural ecological balance.”  More than 29,000 wild horses and burros are being managed by the BLM in their herd management areas.  Natural predators leave the wild horses unchecked, and the growth rate of 18-25 percent is common.

The land’s vegetation is overtaxed, which affects herd health and native wildlife. However, “gathers” cull the herd growth.  Every 3-5 years, animals are rounded up. Younger animals are offered for public adoption. Those older horses are offered for sale to good homes and the excess number are kept in a pasture holding area for the rest of their lives.

BLM, along with the U.S. Geological Survey, began a program to investigate fertility control, habitat assessment, and health. The Strategic Research Plan for wild horses and burros management was developed and focused on fertility control and population estimation of these wild animals. This project was taken on in conjunction with the Wild Horse Identification and Management System or WHIMS. Population estimation investigates the impact of fertility control measures on herd behavior as well as analyzing genetic and other changes over time. The resulting findings and products will continue helping the science necessary for guiding decisions for the horses, burros and landscaping.