FORAGING BEHAVIOUR AND SITE SELECTION OF BARNACLE GEESE Branta leucopsis IN A TRADITIONAL AND NEWLY COLONISED SPRING STAGING HABITAT

leucopsis stop to feed on the archipelagos of the Helgeland district, up to 50 km out to sea off western Norway. However, since 1980 an increasing part of the population has moved to a newly exploited agricultural habitat closer to the mainland. This paper compares the foraging performance of geese using the traditional and the new area. Differences between the habitats include asymmetries in time budgets, plant quality, feeding performance and abdominal fatness. We speculate on the relative merits of remaining in previ-ously experienced habitats or moving to unexplored areas. There is some indication that younger geese are less loyal to old sites and are moving to the agricultural habitat. In 1988 18.3 % of the geese using the agricultural fields successfully brought offspring back to Scotland compared to 9.6 % for the outer island birds, although this difference was not statistically signifi-cant