| Remarks |
Nearshore feeder (Ref. 87784). Pursuit diver; coastal; <15 km; water <20m deep (Ref. 356). Based on stable isotope analysis (SIA) diet study of egg albumin, belongs to higher N signature group (based on ratios of stable isotopes of nitrogen and carbon): piscivorous with pelagic foraging range. Aquatic courtship display such as calling and wing-raising, head dipping below the sea surface, and flipping below the sea surface or skittering. Typically nests in crevices. On the Farallon Islands, this species usurps nests of smaller Cassin's Auklet by destroying eggs or chicks thereby effectively lowering its habitat competitor's reproductive success. Severely affected by El Niño events by abandoning nesting attempts in the Farallon Islands in central California. Vulnerable to oil spill as a diving species; population still depressed, with over 50% decline, 9 years after the 1989 Exxon Valdez oil spill in Prince William Sound as an effect of persistent trace oil in the water that caused a decline in forage fish abundance (Ref. 87784). |
