The Proposed Action would involve gathering an estimated 240 wild horses, 66 wild burros, removing approximately 157 excess wild horses, 66 excess wild burros, and releasing 60 wild horses back into the Garfield HMA after treating/retreating an estimated 26-33 mares with the fertility control vaccine (PZP-22) and adjusting the sex ratio to favor males. The estimated 157 excess wild horses to be removed includes 85 excess wild horses which are established on lands within the Marietta Wild Burro Range HMA. The use of the PZP-22 should maintain AML range by reducing the population growth rate and reduce the number of excess wild horses that would need to be removed in the future. Should the gather efficiency exceed 80% of the current wild horse populations, additional mares (up to 33) would be treated and released back to the Garfield Flat HMA. The BLM intends to continue with this treatment protocol by returning to Garfield Flat every 2-3 years to maintain AML by continuing the population control protocols of gathering and re-treating the mares with PZP. If gather efficiencies utilizing a helicopter does not achieve the desired goals of the Proposed Action, water/bait trapping may be utilized to capture sufficient numbers of horses to achieve these targets.
The management actions contained within the proposed action are also supported by a recent report received from the Humane Society of the United States (HSUS) which recommends that the BLM increase the level of use of fertility control and other population control methods (sex ratio adjustments, geldings, etc.).