Burrowing Owls effected by Priairie Dog Poisons
by Alan Wilson - (Washington, D.C., October 16 , 2012) Defenders of Wildlife, American Bird Conservancy, Natural Resources Defense Council, and Audubon of Kansas have urged the Environmental Protection Agency (EPA) to reject an application by Scimetrics to use the rodenticide Kaput-D for the control of black-tailed prairie dogs in Colorado, Kansas, Nebraska, New Mexico, North Dakota, Montana, Oklahoma, South Dakota, Texas and Wyoming.
The groups say that because Kaput-D, which contains the anticoagulant diphacinone that causes poisoned animals to bleed to death, is not selective in the animals it impacts, it has a high probability of killing non-target wildlife, including species protected under the Endangered Species Act, the Bald and Golden Eagle Protection Act, and the Migratory Bird Treaty Act.
Black-tailed prairie dogs are regularly exterminated from ranchland as pests, primarily because they are thought to compete with cattle for forage. Their populations have been reduced by as much as 95 percent of their historical numbers and continue to decline.
In a letter to the EPA, the groups point out that the proposed registration decision is based on information provided by the U.S. Fish and Wildlife Service (FWS) for another pesticide, Rozol Prairie Dog Bait, which contains a different active ingredient, chlorophacinone.
The groups stress that the EPA cannot simply insert Kaput-D in place of Rozol in its scientific assessment. They advise EPA to complete formal “Section 7” Endangered Species Act (ESA) consultations with FWS on endangered species impacts from the use of this specific pesticide. They suggest that EPA complete such a consultation prior to registration, both to avoid litigation risk, and so that endangered species concerns may properly be analyzed and necessary use restrictions incorporated.
“EPA cannot simply piggy-back onto another prior consultation for an entirely different active ingredient. Registration of Kaput-D prior to completion of Endangered Species Act consultation violates the Act,” said Dr. George Fenwick, President of American Bird Conservancy.
Diphacinone causes internal hemorrhaging and damage to capillaries throughout the body. Affected animals exhibit differences in behavior or weakness prior to death, which makes them susceptible to predators that in turn become poisoned. By the time the targeted the animal expires or is predated upon, it may be carrying in its system a “super dose” of the rodenticide, which can result in secondary poisonings of non-target species, including much larger animals such as eagles and badgers.
Prairie dog colonies are used by many protected wildlife species that prey on or scavenge prairie dogs or use their burrows for shelter. The use of rodenticides in and around prairie dog burrows can have significant impacts on animal populations beyond the intended target. The proposed label change would make this product available for this use throughout the range of the prairie dog, an area covering 2.4 million acres in the western United States. Numerous species will be impacted by this use.
Birds and non-target mammals that feed on grain-based baits are at risk of direct poisoning. Field applications endanger a broad spectrum of grassland birds, including prairie-chickens and sage-grouse, as well as songbirds such as the Western Meadowlark, and shorebirds such as the Upland and Mountain Plovers. Prairie-chickens and sage-grouse are species of special concern that are being considered for possible ESA listing. Non-target predatory and scavenging species at risk of secondary poisoning include the highly-endangered black-footed ferret, as well as badgers, coyotes, foxes, raccoons, skunks, Bald Eagles, Golden Eagles, hawks, and owls.
Raptors are highly susceptible to secondary poisoning from some of the chemicals used in rodenticides. They can spot dead or dying black-tailed prairie dogs that are more difficult to see from a ground-level perspective, and they have been observed to be attracted to Rozol-poisoned prairie dog colonies. The Golden Eagle, Ferruginous Hawk, and Burrowing Owl are among nine species with documented dependence on prairie dog colonies. All three have been identified as being of “Species of Conservation Concern,” defined as species that are likely to become candidates for listing under the ESA without additional conservation action. Further, Bald and Golden Eagles are protected under the Bald and Golden Eagle Protection Act. In particular, Golden Eagle populations appear to be experiencing declines throughout most of their range, and the availability of poisoned prey is expected to exacerbate population declines.
The groups also take issue with the premise of approving yet another product to eradicate the black-tailed prairie dog, which has suffered massive declines throughout its range due to poisoning and disease. The registration of Kaput-D is likely to result in expanded prairie dog poisoning, thus increasing the likelihood that the species will itself require federal endangered species protection in the future.
In their letter, the three groups say that “EPA should also consider the impacts of an increasingly poisoned landscape on future black-footed ferret recovery efforts. Elimination of more prairie dogs and their burrows from the landscape due to poisoning will undoubtedly diminish the future success of ferret recovery by reducing the number of suitable sites for reintroduction and restoration.”
Given the magnitude of the impact to non-target wildlife, and given that use of this product will almost certainly result in the death of birds in violation of the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act, the groups are asking EPA to deny the proposed registration.
American Bird Conservancy (ABC) is a 501(c)(3) not-for-profit membership organization whose mission is to conserve native birds and their habitats throughout the Americas. ABC acts by safeguarding the rarest species, conserving and restoring habitats, and reducing threats, while building capacity in the bird conservation movement.