Vagrancy of Brünnich’s Guillemot Uria lomvia in Europe

Abstract

We review the occurrence of vagrant Brünnich’s Guillemots Uria lomvia in Europe. The 104 records of 109 individual birds that could be traced showed a distinct seasonal pattern. There were no September records, but a small autumn peak was apparent in late October and early November. Numbers increased again in early December, peaked in late January and early February, and declined through spring, with only seven records in summer. Autumn records were mostly of first-winter birds, whereas relatively more adults were recorded in winter, in line with expectations based on timing of migration for these different age classes. We speculate that vagrant birds to western Europe have strayed from the wintering grounds and migration routes south of Iceland and along the Norwegian coast, while overland movements from the Barents Sea may explain inland records from northern Scandinavia, and some from the Baltic Sea. Two spatial clusters of records were evident, one in Scotland and the other in the Skagerrak, Kattegat and southern Baltic Sea. Between 1975/76 and 2005/06, the number of records declined in the former region but increased in the latter, which may represent a real decrease in occurrence, and increased observer effort, respectively.