Effects of Anthropogenic Food Sources on Movements, Survivorship, and Sociality of Common Ravens in the Arctic

Abstract

Abstract We investigated survivorship, movements, and sociality of Common Ravens (Corvus corax) exploiting concentrated food resources at a landfill in Greenland. From 1992–1995 we banded 383 ravens: 365 were captured at the landfill and 18 were banded in nearby nests. Thirty-nine ravens were recovered, most by shooting (87%). Mean number of days survived post-banding (494 ± 97) did not differ among age groups, but a higher proportion of juveniles was recovered. Ravens migrated west and south to the coast during winter. No difference existed among age groups in mean distance between locations of banding and recovery (151 ± 31 km). Number of ravens congregating at the landfill declined during the study, coinciding with a decrease in the local human population. Harsh winter climate, limited ice-free land, and abundant human refuse influenced raven use of the wilderness landscape by facilitating the formation of large, nomadic foraging groups.