Proceedings of the Vertebrate Pest Conference

The black-tailed prairie dog occupies an estimated 2.4 million acres in the western U.S and is considered to be a keystone species of the Great Plains due to its influence on biological diversity and ecosystem function. Over 200 vertebrate species are known to associate with prairie dog colonies, and there is documentation that at least 9 species exhibit dependence on prairie dogs either for habitat and shelter or as a prey species. Unlike many other burrowing mammals, the prairie dog relies on an open burrow system that results in a significant amount of time spent above ground, rendering them more easily accessible to predatory species. Many species that use the prairie dog as a food source are protected under the Endangered Species Act, the Migratory Bird Treaty Act, and the Bald and Golden Eagle Protection Act, and include the black-footed ferret, both species of eagle, and several species of raptors. The registration and use of the anticoagulant rodenticides chlorophacinone and diphacinone for prairie dog control presents risks to these protected species due to the potential for secondary poisoning. Anticoagulant rodenticides have caused secondary poisoning in laboratory studies and have been responsible for mortality incidents in the field. Since geographically limited registrations began in 2005, a limited number of such incidents associated with prairie dog control have been documented, and these elicit concern for the more widespread use of these rodenticides that would accompany registrations covering the entire range of the black-tailed prairie dog.