The population structure of Greenland Barnacle Geese Branta leucopsis on the wintering grounds on Islay

The population structure of the Greenland Barnacle Goose Branta leucopsis at its main winter haunt, the island of Islay, Scotland, was studied using marked individuals caught at three sites on their breeding grounds in east Greenland and on the wintering grounds on Islay. The distribution of individual geese on Islay was found to be non-random. Birds were generally faithful to restricted groups of sites on the island, both within a winter and between consecutive winters. These groups of sites on Islay held different proportions of the individuals from the three catch sites in Greenland. Birds caught together in Greenland were associating in winter more than would be expected if their distribution were random.