The Use of Estrogen-treated Eggs to Reduce Egg Predation
by Raccoons
BRAD SEMEL AND LOWELL K. NICOLAUS
McGraw Wildlife Foundation, P.0. Box 9, Dundee, IL 60118; Department
of Biological Sciences, Northern Illinois University, DeKalb, IL 60115
The chemical agent, 17 alpha-ethinyl estradiol (estrogen), was used to test its efficacy as a taste aversion agent. Feeding sites were established near wetland habitat where nightly observations enabled us to record food consumption of individually tagged raccoons (Procyon lotor). Free-ranging animals were not able to distinguish between chemically treated and untreated eggs. Reduced consumption of eggs was recorded for individual raccoons following consumption of estrogen-treated eggs. In addition, treated males often avoided feeding sites on nights when eggs were present. Raccoons that were not treated continued to open and consume eggs freely. This is the first time acquisition of conditioned taste aversion has been documented (video recordings) in free-ranging raccoons. Implications for using estrogen-treated eggs to establish conditioned aversion are discussed.
Previous Section -- Developing a Strategy of Predator Control for the Protection of the California Least Tern: A Case History
Return to Contents
Next Section -- Reducing Egg Predation with Estrogen-based Conditioned Taste Aversion
