Taste-Aversion Conditioning of Crows to Control Predation on Eggs

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Science  08 Apr 1983:
Vol. 220, Issue 4593, pp. 212-214
DOI: 10.1126/science.220.4593.212


Free-ranging crows (Corvus brachyrhynchos) that ate chicken eggs that were painted green and contained a nonlethal toxin subsequently avoided green eggs at various locations, whether or not they contained toxin. The crows also continued to eat unpainted and nontoxic chicken eggs. Illness-induced aversions among predators in nature may be a powerful determiner of the evolution of Batesian mimicry and, in human hands, serve as a practical tool for wildlife ecologists.