Diethylstilbestrol as a Temporary Chemosterilant to Control Black-tailed Prairie Dog Populations

Abstract

Controlling reproduction in pest rodent populations may be preferable to using lethal rodenticides. The effectivenss of diethylstilbestrol (DES), a synthetic estrogen, as a reproductive inhibitor in female black-tailed prairie dogs (Cynomys ludovicianus) was examined in a 4-year study at Wind Cave National Park, South Dakota. In 1979 and 1980, a study colony was monitored to determine age structure, reproductive success of individual animals, and rate of colony expansion. In 1981, the colony was divided into control and experimental areas. Application of DES-treated oats (.11% active ingredient) during the breeding season resulted in complete curtailment of reproduction in the experimental group while reproduction in the control group was normal. Results were identical in 1982 when treatment was reversed. There were no obvious effects of DES treatment on subsequent reproductive capability of study animals. In 1981, surface expansion of the study colony was 4X less on the DES-treated side compared with control.