Guide to North American Birds
Conservation status Population still in the millions, but reported declines of 20%-50% in some large colonies in recent decades are cause for concern. Eggs and adults harvested for food by natives in some Arctic areas. Bigger threats to survival are large numbers killed in fishing nets, and vulnerability to pollution, oil spills, and effects of climate change.
Family Auks, Murres, Puffins
Habitat Ocean, nesting colonially on ledges of sea cliffs. Favors very cold ocean waters of Arctic; when not nesting, often very far from land over deep waters. May associate with edges or openings in pack ice. Nests on rocky coasts or islands with steep cliffs.
A large, robust auk, swimming and diving deep in cold ocean waters. Very similar to Common Murre. The two are found together in many areas, even nesting on the same ledges of rocky northern islands, but the Thick-billed has its center of abundance farther north. Despite major recent declines, its population in the eastern Canadian Arctic undoubtedly runs into the millions.

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Feeding Behavior

Forages while swimming underwater. May dive to more than 200' below surface.


Eggs

One. Very variable, usually whitish, tan, blue, or green, with markings of brown and black. Incubation is by both sexes, 30-35 days. One parent is almost always at nest throughout nesting cycle. Young: Fed by both parents. Adults often forage many miles away from colony. Young leaves nest at 15-30 days, before able to fly; glides down to sea, accompanied by adult male. Young evidently is accompanied and cared for by male for several weeks after leaving nest.


Young

Fed by both parents. Adults often forage many miles away from colony. Young leaves nest at 15-30 days, before able to fly; glides down to sea, accompanied by adult male. Young evidently is accompanied and cared for by male for several weeks after leaving nest.

Diet

Mostly fish. Diet is primarily fish in summer (and young are fed almost entirely on fish); may include more crustaceans in winter. Fish in diet include cod, herring, capelin, sand lance, sculpin, many others. Crustaceans eaten include shrimp, amphipods, mysids, copepods. Also eats some marine worms, squid.


Nesting

Probably older than 3 years at first breeding. Nests in colonies, some very large. Some pair formation may occur before arrival at colony. At nest site, members of pair bow, nibble at each other's bills; may pick up pebbles and present them to each other. Nest site is on cliff ledge; may use narrower and smaller ledges than Common Murre. No nest, egg laid on bare rock.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

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Migration

Some remain through winter as far north as open water allows, including around openings in pack ice. Others move south. Regular in winter on waters off New England, has strayed farther south. In west, very rare south of Alaska in winter.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon

See a fully interactive migration map for over 450 bird species on the Bird Migration Explorer.

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Songs and Calls

Similar to Common Murre: low, purring murrrr; also croaks and growls on breeding grounds.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
Learn more about this sound collection.