COMMON RAVENS ARE ATTRACTED BY APPEASEMENT CALLS OF FOOD DISCOVERERS WHEN ATTACKED

When adult territorial Common Ravens (Corvus corax) aggressively defen d carcasses from vagrant immatures, both dominant and subordinate imma ture birds respond with begging postures and vocalizations. We demonst rated through experiments in an aviary complex that these vocalization s attract other ravens that then learn of new feeding opportunities. N earby free-ranging ravens also are attracted to begging vocalizations. Begging is most common when six or fewer immatures interact with adul ts. Typically, fewer than five birds are attracted locally to begging vocalizations, a number that is not sufficient to account for the larg e numbers of ravens that eventually assemble at a carcass. Most of the recruitment to carcasses, therefore, cannot be explained by attractio n to local vocalizations alone. Received