Brunnich's Guillemot
Thick-billed & Common (centre) Murres
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: Animalia : Chordata : Aves : Charadriiformes : Alcidae : Uria : lomvia
Binomial name
Uria lomvia (Linnaeus, 1758)

The Brunnich's Guillemot, or Thick-billed Murre, Uria lomvia, is a bird in the auk family. It breeds on coasts and islands in the high Arctic of Europe, Asia and North America.

These birds breed in large colonies on coastal cliffs, their single egg being laid directly on a cliff ledge. They move south in winter into northernmost areas of the north Atlantic and Pacific, but only to keep in ice-free waters. The larger size of this species makes it less prone than the Little Auk to be carried further south by late autumn storms, and they are consequently rare in temperate latitudes.

At 40-44 cm in length, with a 64-75 cm wingspan, this species is only marginally larger than the closely related Common Guillemot.

Adult birds are black on the head, neck, back and wings with white underparts. The bill is long and pointed. They have a small rounded black tail. The lower face becomes white in winter. They differ from Common Guillemot in their thicker bill, darker back and white gape stripe. In winter, there is less white on the face.

The Brunnich's Guillemot's flight is strong and direct, and they have fast wing beats due to the short wings. They look shorter than Common Guillemot in flight. These birds forage for food like other auks, by swimming underwater. They mainly eat fish, also some crustaceans and other small invertebrates.

This species produces a variety of harsh cackling calls at the breeding colonies, but is silent at sea.

This bird is named after the Danish zoologist Morten Thrane Brunnich.