[Breeding biology of the whiskered auklet (Aethia pygmaea): postnesting period]

This is the third paper on the breeding biology of the whiskered auklet on Buldir Island (Aleutian Islands) based on material collected in 1993. Unlike other alcid birds, both adult and young whiskered auklets returned to the colony the night after the end of the breeding season. From the end of July until the third ten-day period of August, the number of adult birds that returned to the island was at approximately the same level, and then decreased, while the number of young birds that returned to the islands markedly varied, and peaks were noted every 5-8 nights. Adult birds continued to visit all the nest habitats, but not all nest chambers were visited equally frequently. In the first and third ten-day periods of August, the auklets visited 61% and 19.8% of the nest chambers, respectively. It remains unclear whether they were their hosts, or other birds used their nests for the next year. The return of adult and young birds to the colony to sleep after the breeding season appears to be related to the settled mode of life of the whiskered auklet and its feeding near the islands in water perturbations caused by tidal currents.