| Remarks |
Inhabits the continental shelf; <100 km (Ref. 356). One of the largest global population of seabirds at >10 million individuals. Slender-billed fit for predominantly fish diet. Feed on sandeels (Ammodytes marinus) and capelins (Mallotus villosus) . Based on stable isotope analysis (SIA) diet study of egg albumin, belongs to lower N signature group (based on ratios of stable isotopes of nitrogen and carbon) indicating a more planktivorous diet early in the breeding season and shifts to a piscivorous diet when raising its chicks in late summer (Ref. 87784). Displays pursuit diving behavior (Ref. 356). Carry prey in their bills back to their colony; adults feed their chicks with regurgitated food; breeding pairs sharing incubation and chick-rearing duties (Ref. 95711). With flexible time-budgets that allow adults more feeding time during lean years. Breed in colonies on cliff sides. Vocal interactions in the colony by way of repeated waves of calling sounds. Fostering recorded with Thick-billed murres (Uria lomvia). Appeasement or fight avoidance posture in incubating birds include turning away and flattening themselves against a cliff. Semi-precocial. Chicks leave nest after attaining 25% of adult body mass. Highly vulnerable to environmental pollution such as PCB pesticide pollution reported on Long Island in the early 1970s and oil pollution from the Exxon Valdez in Prince William Sound, Alaska in 1989, and the Apex Houston oil spill in 1986 off the Californian coast. High levels of selenium reported in eggs and tissues of birds from Puget Sound that is linked to lower survivability and reproductive failure due to kidney and liver damage and congenital deformities. The 1993 ENSO event in the Gulf of Alaska saw mortality in the thousands due to starvation. Globally most widely affected by mortality due to fishing net entrapment recorded in northern Norway, the western Bering Sea, the Farallon Islands, waters off eastern Newfoundland, western Greenland (Ref. 87784). |