Ecological segregation among plankton-feeding alcidae (aethia-a and cyclorrhynchus) ...

• Main Author: Bedard, Jean
• Format: Text
• Language: English
• Published: University of British Columbia 2012
• Subjects: North Atlantic; St Lawrence Island; Alaska
• Online Access: https://dx.doi.org/10.14288/1.0106803; https://doi.library.ubc.ca/10.14288/1.0106803

Among the North Atlantic marine birds, only one species fills the plankton-feeding niche (Plautus alle L., Alcidae) while in the North Pacific and adjacent seas, no less than five alcids occupy it. A comparison of the feeding and nesting habits was made in order to understand how the food resources and the nesting habitat were partitioned between three of these species, the Crested auklet (Aethia cristatella (Pallas)), the Least auklet (A. pusilia (Pallas)) and the Parakeet auklet (Cyclorrhynchus psittacula (Pallas)), The study was made on St. Lawrence Island, Alaska, during the summers of 1964- to 1966. The two congeneric species differ markedly in size (pusilla 90 g; cristatella. 300 g) the Crested and the Parakeet auklets are of equivalent body size. The three species have diurnal habits. The two Aethia are active on the nesting colonies during the morning and the evening and feed at sea in early afternoon and early morning. Cyclorrhynchus is present on the colonies in the morning and early afternoon only ...