Breeding Biology of Crested, Least, and Whiskered Auklets on Buldir Island, Alaska

Nest site characteristics, breeding phenology, productivity, and mortality factors were evaluated from 1974 to 1976 for the Crested Auklet (Aethia cristatella), the Least Auklet (A. pusilla), and the Whiskered Auklet (A. pygmaea), which nested together in a colony at Buldir Island in subarctic Alaska. These species were compared and data from Buldir were compared with those from previous studies at an arctic colony. The auklets actively competed for nest sites and differed in their choice of site substrates. Crested Auklets, the largest of the three, used the largest nest crevices. Breeding activities occurred on Buldir from mid-May to mid-August. Crested Auklets had a slightly longer nesting period than the other species. Reproductive success (fledglings/eggs) was approximately 50% for Crested and Least auklets, and apparently higher for Whiskered Auklets. Little predation on eggs or chicks was recorded, but avian predators were the major cause of adult auklet mortality.