Unspecialized exploitation of small carcasses by birds

During the winters of 1981–82 and 1982–83 we studied scavenging birds feeding on 14 Greylag Goose carcasses and intra- and inter-specific interactions occurring among them. The bird species most often visiting this carrion were: Red Kite, Magpie, Raven, White Stork, Marsh Harrier, Spanish Imperial Eagle, Griffon Vulture, Black Vulture, Grey Heron, Buzzard and Lesser Black-backed Gull. Each species' frequency at visiting carrion was not directly related to the abundance of the species in the area, but seemed to be related to inter and intraspecific competition, distance to roosts, and the economic return obtained from eating carrion. These species were not social at carrion, aggresion often taking place among them. Large sized species dominated smaller ones. We discuss similarities and differences of carrion exploitation in this bird guild and Old and New World Vulture guilds.