Within-winter movements and site fidelity of Icelandic Greylag Geese Anser anser

Abstract

Capsule: Levels of mobility and turnover changed at different stages of the non-breeding season. Aims: To describe the pattern of within-winter movements of Icelandic Greylag Geese in northern Britain and to assess the rate of turnover at different stages of the non-breeding season. Methods: Sightings of marked individuals were used to describe movements throughout the wintering range, while more detailed local studies were used to assess rates of turnover. Results: Greylag Geese were most mobile and turnover greatest during the early winter period (October-December). Birds were least mobile and turnover lowest during the midwinter period. In spring (March-April) rates of turnover slightly increased as did movement between areas. Despite this it seemed that most birds probably made a direct flight to Iceland from their final wintering area without staging in north Scotland. Conclusions: Greylag Geese were highly mobile, particularly on arrival from their Icelandic breeding grounds. They were less mobile in midwinter and spring. There was little evidence of a northerly return movement within Britain in spring. Most departed to Iceland directly from their final wintering locations. Evidence of an expansion in the known range is also presented. © 2005 British Trust for Ornithology.