The thick-billed murre or Brünnich's guillemot (Uria lomvia) is a bird in the auk family (Alcidae). This bird is named after the Danish zoologist Morten Thrane Brünnich. The very deeply black North Pacific subspecies Uria lomvia arra is also called Pallas' murre after its describer.
Taxonomy The thick-billed murre was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. He placed it with the other auks in the genus Alca and coined the binomial name Alca lomvia. Linnaeus specified the type locality as boreal Europe but this was restricted in 1921 to Greenland by the German ornithologist Ernst Hartert. The thick-billed murre is now placed together with the common murre in the genus Uria that was introduced in 1760 by the French zoologist Mathurin Jacques Brisson. The genus name is from Ancient Greek ouria, a waterbird mentioned by Athenaeus. The specific epithet lomvia is a Swedish word for an auk or diver. The English "guillemot" is from French guillemot probably derived from Guillaume, "William". "Murre" is of uncertain origins, but may imitate the call of the common guillemot. Four subspecies are recognised:
U. l. lomvia (Linnaeus, 1758) – coastal northeast, southeast Canada, Greenland, Iceland, Jan Mayen (northeast of Iceland), north Scandinavia, Svalbard (north of Norway) to Novaya Zemlya (northwest Russia) U. l. eleonorae Portenko, 1937 – coastal east Taymyr Peninsula to New Siberian Islands (central north Russia) U. l. heckeri Portenko, 1944 – Wrangel and Herald Islands (north of northeast Siberia) and Chukchi Peninsula (northeast Siberia) U. l. arra (Pallas, 1811) – coastal Kamchatka Peninsula, Sea of Okhotsk, Kuril Islands and Commander Islands (east Russia), Aleutian Islands, west, southeast Alaska, north Yukon (northwest Canada)
Description
Since the extinction of the great auk in the mid-19th century, the murres are the largest living members of the Alcidae. The thick-billed murre and the closely related common guillemot (or common murre, U. aalge) are similarly sized, but the thick-billed murre is larger in both average and maximum size. The thick-billed murre measures 40–48 cm (16–19 in) in total length, spans 64–81 cm (25–32 in) across the wings and weighs 736–1,481 g (26.0–52.2 oz). The Pacific race (U. l. arra) is larger than the Atlantic race, especially in bill dimensions. 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. This species produces a variety of harsh cackling calls at the breeding colonies, but is silent at sea. They differ from the common murre in their thicker, shorter bill with a white gape stripe and their darker head and back; the "bridled" morph is unknown in U. lomvia – a murre has either a white eye-stripe, or a white bill-stripe, or neither, but never both; it may be that this is character displacement, enabling individual birds to recognize conspecifics at a distance in the densely packed breeding colonies as the bridled morph is most common by far in North Atlantic colonies where both species of guillemots breed. In winter, there is less white on the thick-billed murre's face. They look shorter than the common murre in flight. First-year birds have smaller bills than adults and the white line on the bill is often obscure, making the bill an unreliable way to identify them at this age. The head pattern is the best way to distinguish first-year birds from common murres.
Distribution and habitat
The thick-billed murre is distributed across the polar and sub-polar regions of the Northern Hemisphere where four subspecies exist; one lives on the Atlantic and Arctic oceans of North America (U. l. lomvia), another on the Pacific coast of North America (U. l. arra), and two others that inhabit the Russian Arctic (U. l. eleonorae and U. heckeri). Thick-billed murres spend all of their lives at sea in waters which remain below 5°C, except during the breeding season when they form dense colonies on cliffs. They move south in winter into northernmost areas of the north Atlantic and Pacific, but only to keep in ice-free waters.
As a vagrant Brünnich's guillemot is a rare vagrant in European countries south of the breeding range. In Britain, over 30 individuals have been recorded, but over half of these were tideline corpses. Of those that were seen alive, only three have remained long enough to be seen by large numbers of observers. All three were in Shetland - winter individuals in February 1987 and November/December 2005, and a bird in an auk colony in summer 1989. The 1989 and 2005 birds were both found by the same observer, Martin Heubeck. The species has been recorded once in Ireland, and has also been recorded in the Netherlands. In the western Atlantic, they may range as far as Florida, and in the Pacific to California. Before 1950, large numbers appeared on the North American Great Lakes in early winter, passing up the St. Lawrence River from the East coast. Such irruptions have not been seen since 1952.
Behaviour and ecology
Breeding
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