RENO, Nev. (AP) -- The U.S. Bureau of Land Management plans to step up temporary roundups of wild horses to treat the animals with fertility control drugs before releasing them back to the range instead or permanently removing them from public lands.
The agency plans 11 gathers of wild horses on federal land in Nevada, Idaho and Utah in the coming year for the primary purpose of applying the vaccine to about 890 mares.
"If these fertility control treatments prove successful, we can lengthen the time between some gathers, saving taxpayer dollars," BLM Director Bob Abbey said Wednesday.
Horse protection advocates said the temporary roundups are a step in the right direction but complained that the strategy will be used in less than one-fifth of BLM gathers planned in the coming year.
Suzanne Roy, campaign director for the American Wild Horse Preservation Campaign, said the federal agency failed to mention in its announcement that it intends to round up an estimated 47 other herds and permanently remove over 11,000 wild horses from the range after removing about 10,000 this year.
"Unfortunately, the department is continuing business as usual and ignoring tens of thousands of citizens who have voiced their opposition to the mass roundup and removal of America's wild horses from the West," Roy said.
Roy said the majority of the horses are warehoused in government long-term holding facilities, costing American taxpayers tens of millions of dollars annually.
The BLM says permanent roundups also are needed because the 38,000 wild horses and burros that roam public rangelands in 10 western states cannot be sustained by the land.
The agency maintains the appropriate number of horses and burros is about 26,600.
BLM officials said the population of wild horses on public rangeland doubles about every four years because the animals have virtually no natural predators.
The agency said in the case of the temporary gathers, it will be using the fertility control vaccine Porcine Zona Pellucida, or PZP, which makes mares temporarily infertile.
PZP is not available commercially, but the BLM uses it in cooperation with the Humane Society of the United States under Food and Drug Administration rules that apply to research on new animal drugs.
Agency officials said PZP was first tested on the wild horses of Assateague Island off the coasts of Maryland and Virginia, where a reduction in mare pregnancy rates was observed.
Most of the "catch, treat and release" gathers in the coming year are planned in horse management areas in Nevada. One is planned in Utah and two in Idaho.
Copyright 2010 The Associated Press.