Uria aalge; guillemots (syn: common murres) are common auks of Iceland as well as in Europe as a whole. On land they look slender with their relative long necks. However, in flight they retract their necks so they can easily be confused with other members of the auk group. Next to the typical form the "bridled" form can be found commonly on the cliffs of Iceland. The latter has a white circle around the eye with an extension backwards suggesting they are wearing spectacles. The common guillemot can easily be confused with the Brünnich's guillemot, in fact almost indistinguishable when observing them flying over sea (see details Brünnich's guillemot). The guillemots breed in dense colonies of steep cliffs. Only 1 egg is laid on bare edges. Guillemot breeding colonies can be found on sea cliffs along the Atlantic coast of France, the British isles, further north and west to Iceland, Norway, north east to the Kola peninsula of northern Russia. Outside the breeding season they can be found all over the eastern Atlantic: from north of Russia, Norway to Iceland and south to the Portuguese coast, and also on the North Sea and Baltic Sea.