Feeding Behavior

Forages while swimming underwater. Catches most food 5-20' below surface, rarely may dive to 30'. May catch several fish during one dive. Sometimes steals fish from puffins or other auks.

Eggs

1, perhaps rarely 2. Tan or greenish to white, variably marked with brown. Incubation is by both sexes, 32-39 days. Young: Both parents bring fish in bills to feed nestling. Young leaves nest 14-25 days after hatching, before able to fly. Late in evening, young follows adult to cliff edge and then flutters down to water, and adult and young swim away.

Young

Both parents bring fish in bills to feed nestling. Young leaves nest 14-25 days after hatching, before able to fly. Late in evening, young follows adult to cliff edge and then flutters down to water, and adult and young swim away.

Diet

Mostly fish. Feeds mainly on small fish, especially sand lance, also herring, sprat, capelin, stickleback, cod. Also eats crustaceans and marine worms.

Nesting

Usually first breeds at age of 4-5 years. Nests in colonies. May mate for life. Pair formation may take place within flocks on water or on common ground near colony. In display, male raises head, pointing bill up while giving growling call, then bows deeply; female sometimes does same. Members of pair also touch bills, preen each other's feathers. Nest site is in crevice in cliff, under boulders, on ledge, or in abandoned burrow of other species. Sometimes no nest built, usually small collection of pebbles, grass.