And for a tiny colony of birds, such as the one at Elephant Butte, it could quickly lead to extinction. Based on Mehlhop's work, the Bureau of Reclamation, which manages Elephant Butte and 6,000 acres of surrounding lands, began trapping cowbirds in 1996. Over two months, biologists caught an astounding 1,200 birds. The Santa Fe-based Forest Guardians threatened the bureau with a lawsuit, claiming that the agency would be illegally harming the flycatcher, which is protected under the Endangered Species Act, if it allowed grazing in the area. Ranchers say they were caught by surprise.
Science is central to the ranchers' appeal of the decision.
They claim there is no proof cows have brought in the cowbirds that have parasitized the flycatcher nests. They also point to a study done along Arizona's Gila River where cows and flycatchers appear to both be thriving. In fact, only a few flycatchers currently inhabit the 21 million acres of national forest in the region, but there are hundreds of miles of unoccupied, potential habitat along streams. And cattle graze virtually every acre. Bud Eppers, president of the New Mexico Public Lands Council, which represents 3,500 public lands ranchers in New Mexico, says he worries the Forest Service restrictions could drive some ranchers out of business.