The Adaptive Significance of Avian Mobbing

Three experiments were performed to test information carried by mobbing of European blackbirds (Turdus merula). They showed that mobbing alerts conspecifics as well as the mobber itself, supporting the “alerting others” hypothesis. Mobbing gives directional information about the predator's location. Mobbing is enhanced by the predator's movement in agreement with the “perception advertisement” hypothesis. Several other aspects of relations between the mobber and conspecifics were studied and discussed.