Federal officials estimate there are more than 82,000 wild horses and burros on public rangelands as of March 1, 2022. That’s nearly three times what they consider a manageable amount.
In an attempt to reduce population growth rates, the BLM recently approved two fertility control vaccine trials, which will be conducted at a corral in Carson City, Nev. Nevada's roughly 46,000 wild horses and burros account for more than half of the West’s population.
Without management, populations can double every four to five years, said Jenny Lesieutre, public affairs specialist with BLM’s Nevada wild horse and burro program.
“That's going to affect the scientific dynamics of the land itself, and the other animals that require the same forage and water,” Lesieutre said.
One study, led by the U.S. Department of Agriculture Animal and Plant Health Inspection Service’s National Wildlife Research Center, will experiment with variations of the oocyte growth factor vaccine to identify which offers the longest-lasting contraception from a single dose.
The other study, led by scientists associated with Cornell University College of Veterinary Medicine and Northwest Wildlife Conservation Research, will test if vaccines that require more than one dose last longer when injected in a horse's flank or neck muscle.
Independent animal care personnel will help oversee the welfare of the horses during the trials, said Lesieutre, adding that the studies will span three to five years.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
