Feeding Behavior

Forages in flight by dipping to surface of water, or by picking up items while swimming; scavenges on land, and catches smaller birds in the air. Often harasses other birds, forcing them to drop their food.

Eggs

2, rarely one. Brownish to olive or pale blue, usually with dark brown spots around larger end. Incubation is by both sexes, 26-32 days. Young: May leave nest shortly after hatching, but remain in vicinity. Female stays with young most of time, while male brings back food to feed them by regurgitation. Young capable of flight about 40-50 days after hatching; may become independent soon thereafter, or not for almost 3 weeks.

Young

May leave nest shortly after hatching, but remain in vicinity. Female stays with young most of time, while male brings back food to feed them by regurgitation. Young capable of flight about 40-50 days after hatching; may become independent soon thereafter, or not for almost 3 weeks.

Diet

Mainly fish, birds, carrion. At sea eats mostly fish, particularly species like sand lance which gather in dense schools. Around breeding colonies often preys heavily on smaller seabirds, including kittiwakes and puffins, and eats eggs and chicks of many species. Also eats carrion, insects, and small mammals up to size of rabbits.

Nesting

Usually first breeds at age of 7-8 years. Nests in loose colonies. Pair formation occurs in neutral social areas within or near colony, with much posturing and calling. Nest site is on ground, in open area. Nest (built by both sexes) is shallow depression lined with bits of plant material. In aggressive display near nest, both wings are raised together over back, head extended forward while bird gives harsh calls.