Energetics of little auks (Alle alle) breeding around the Greenland Sea

The energy demands of Little Auks are relatively high because their wing loading (ratio of body mass to wing area) is extremely high, and distances to foraging areas are often long. The energy expenditure of Little Auks is therefore an important parameter; if parents are already working near maximum capacity during chick-rearing they may have little flexibility to increase their foraging effort if food availability decreases. To examine the range and flexibility of parental energy expenditure we conducted doubly-labelled water (DLW) trials during early chick-rearing (low chick food demands) and mid chick-rearing (peak chick-feeding demands) at different colonies with highly contrasting oceanographic conditions and food availability.