Nesting habitat relationships of four species of alcids at Fish Island, Alaska

Abstract

Tufted Puffins, Horned Puffins, Parakeet Auklets, and Pigeon Guillemots were studied at Fish Island, Alaska, 59°52, N, 147°25, W, to determine if nesting habitat relationships indicated nest separa- tion or competition. The timing of early stages of breeding and daily activity patterns overlapped broadly among all species. Aggressive interactions occurred among all species. Tufted Puffins nested in cliff edges and grassy slopes; all species used rocky slopes and cliff faces. Tufted Puffin nests in rocks differed from Pigeon Guillemot and Parakeet Auklet nests in having larger entrance height and area, and they were placed farther from the high tide line. These dif- ferences related to body size and take-off ability, and may be indica- tions of past competition for nest sites. Interspecific interactions and site use by more than one species indicated some competition may have occurred for certain sites. Overall, most evidence indicated competition had little influence on nest site use among species.