The U.S. Bureau of Land Management, concerned about deteriorating conditions at the Pryor Mountain Wild Horse Range, is proposing the use of birth control over the next five years to limit herd growth.
BILLINGS, Mont. The U.S. Bureau of Land Management, concerned about deteriorating conditions at the Pryor Mountain Wild Horse Range, is proposing the use of birth control over the next five years to limit herd growth while the agency works on range improvement projects and a long-term herd plan, an agency official said.
BLM officials also want to use a bait-trapping program this summer to capture and take up to 24 horses off the range, which is in southern Montana and northern Wyoming. Linda Coates-Markle, BLM's wild horse and burro specialist for Montana and the Dakotas, said this and the birth control effort are more humane and less intrusive than traditional round ups that cull horses from the land.
"We have to limit grazing impacts, at least temporarily, until we get out of the drought, and the range has a chance to show an improving trend," she said.
The carrying capacity of the range is just over 140, assuming good range conditions, Coates-Markle said. The current herd size is estimated near 160 horses -- not counting the foals BLM expects this year -- and range conditions cannot be considered good, she said.
The agency has used an immunocontraceptive on older and younger female horses in the herd since 2001, out of concerns for both the health of the land and the horses, Coates-Markle said. Natural mortality -- which likely included mountain lions -- took a heavy toll on younger members of the herd two years ago, and BLM doesn't plan to administer birth control to younger horses as part of their five-year proposal, she said.
The plan calls for giving birth control to mares 11 and older each year through 2010, beginning this summer. The program could be suspended for one year for either 11-year-olds or for 12- to 15-year-old mares if the number of surviving foals falls below a certain level, the agency said.
The vaccine used is 90 percent effective at best, Coates-Markle said, and, so far, has prevented 80 percent to 90 percent of treated mares from having foals in any particular year.
Dave Pauli, a regional director for the Humane Society of the United States, said he believes birth control can be a very effective tool to slow population growth. He said he shares concerns about the health of the land and said there's been talk in some corners for years about possibly expanding the range.
"We're saying, long-term, we would rather have a safe, healthy herd than an overpopulated, stressed herd," he said.
He said he was not familiar with the bait-trapping proposal and could not immediately comment on it.
BLM is taking public comments on its plans. Comments must be postmarked by May 5.
Source: Associated Press