UC Irvine

The authors studied the relationship between the foraging radius and energy economy of A. pusilla breeding in colonies on three islands in the Bering Sea (St Lawrence, St Matthew, and St George Islands). The distance to which auklets commuted on foraging trips varied by more than an order of magnitude c5-56 km), but mean field metabolic rate did not vary significantly among birds from the three islands. The authors modeled the partitioning of energy to various activities and hypothesized that the added cost of commuting incurred by auklets from St Lawrence Island (foraging radius, 56 km) was offset by reduced energy costs while foraging at sea. Data indicated that auklets from St Lawrence Island fed on larger, more energy-rich copepods than auklets from St Matthew Island (foraging radius, 5 km). -from Authors