EPA Registers Harmful Rodenticide, Opens Door to Bird Poisonings

Ferruginous Hawk. Photo: Clipart.com

Conservationists are concerned over a recent Environmental Protection Agency (EPA) decision to register the poison Rozol (chemical name chlorophacinone) to kill prairie dogs. This chemical has been registered in the past to kill pest rodents such as mice and rats, but this new use could also lead to large numbers of birds of prey being poisoned after they feed on the poisoned animals. Landowners are supposed to pick up carcasses found above ground, but animals can die up to three weeks after application, so many prairie dogs will likely be missed, eaten by scavengers before they can be collected, or preyed on before they succumb to the poison.

The Ferruginous Hawk is a species of particular concern in this area, and the black-footed ferret, one of the most endangered mammals in the world, preys exclusively upon prairie dogs. The ferret is listed under the Endangered Species Act, but EPA has failed to undertake mandatory consultations with FWS scientists to ensure that they are not harmed by this new use of Rozol. In addition, EPA has failed to consider the secondary poisoning effects of Rozol on migratory birds.

ABC met in person with EPA officials to object to their handling of the registration process, and Audubon of Kansas wrote a detailed letter to the EPA about its concern with the widespread use of Rozol throughout the Great Plains. Their comment noted that eagles, hawks, swift foxes, badgers, coyotes, and black-footed ferrets all face the prospect of secondary poisoning from Rozol on millions of acres.

There are other rodenticides, such as zinc phosphide, already registered for use on prairie dogs, that have little to no risk of secondary poisoning when used according to label instructions. ABC believes that, given the risks to endangered species and predatory birds, and the availability of an acceptable alternative, the use of Rozol for prairie dogs should be discontinued.