FIELD EXPERIMENTS ON EGG PREDATION BY HOODED CROW CORVUS CORONE CORNIX

Frugis S., Parmigiani S., Parmigiani E. & Pelloni C.



Abstract:

The predation by Hooded Crow on white, cryptic and blotched hen's eggs was observed in experimental situations at three study zones. The time interval between appearence of the Crows and predation decreased with training of the birds, This is not due to the association of the exper imenters presence with the availability of a certain food, as shown by experiments with both eggs and other food. The formation of a "search image", documented by earlier studies, is thus confirmed also for the Carrion Crow. The predatory behaviour during the second and third years of experiments indicate that the specific search image may be retained by rhe Crows for over 8 months without reinforcement.