Wintering survival of insect-eating passerines in southern Europe

Abstract

Capsule Intra-year survival during the winter is high for some insect-eating passerines in northern Iberia. Aims To estimate intra-year survival of insect-eating passerines wintering in northern Iberia. Methods Capture–recapture data from four passerines (European Robins Erithacus rubecula; Common Chiffchaffs Phylloscopus collybita; Firecrests Regulus ignicapillus; and Dunnocks Prunella modularis) captured during four consecutive winters were analyzed using Cormack–Jolly–Seber models. Results Intra-year survival during the winter differed between species, possibly revealing different survival or wintering strategies. Thus, Dunnocks and Firecrests showed survival rates close to 1, whereas Chiffchaffs and Robins had lower survival rates (0.4 and 0.3–0.6, respectively). Transients were detected only in Dunnocks (60%). This strategy in which some birds are resident and others are vagrant is already known for other species, particularly those that feed on plants or change to a more vegetarian diet during the winter. Conclusions Northern Iberia, and particularly its coast, is a good wintering area for several insect-eating species.