Editing Common murre (section)

==Description==
The common murre is {{convert|38|-|46|cm|in|0|abbr=on}} in length with a {{convert|61|-|73|cm|in|0|abbr=on}} wingspan.<ref name = mullarney1999>Mullarney et al. (1999)</ref> Male and female are indistinguishable in the field and weight ranges between {{convert|945|g|lboz|frac=2|abbr=on}} in the south of their range and {{convert|1044|g|lboz|frac=2|abbr=on}} in the north.<ref name = harris1985 >Harris & Birkhead (1985)</ref> A weight range of {{convert|775|-|1250|g|lboz|frac=2|abbr=on}} has been reported.<ref name = "CRC">''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (Editor). CRC Press (1992), {{ISBN|978-0-8493-4258-5}}.</ref> In breeding plumage, the [[subspecies|nominate subspecies]] ''U. a. aalge'' is black on the head, back and wings, and has white underparts. It has a thin dark pointed bill and a small rounded black tail. After the [[plumage|post-breeding]] moult, the face is white with a dark spur behind the eye, and there are often dark streaks on the flanks.<ref name = mullarney1999 /> Birds of the [[subspecies]] ''U. a. albionis'' are dark brown rather than black, most obviously so in colonies in southern [[Great Britain|Britain]]. The legs and the bill are dark grey. Occasionally, adults have been seen with yellow-grey legs. In May 2008, an aberrant adult was photographed with a bright yellow bill.<ref>Blamire (2008)</ref>

The adults moult into breeding plumage in December–February, even starting as early as November in ''U. a. albionis'', and back into winter plumage soon after leaving the breeding colonies in July to August. The plumage of first winter birds is the same as the adult winter plumage. However, their moult into first summer plumage occurs later in the year than in adults. First year birds often remain in winter plumage as late as May, and their first summer plumage usually retains some white feathers around the throat.<ref name = mullarney1999 />

Some individuals in the North Atlantic, known as "bridled guillemots", have a white ring around the eye extending back as a white line. This is not a distinct subspecies, but a [[polymorphism (biology)|polymorphism]] that becomes more common the farther north the birds breed.<ref name = hbw>Nettleship (1996)</ref>

The chicks are downy with blackish feathers on top and white below. By 12 days old, contour feathers are well developed in areas except for the head. At 15 days, facial feathers show the dark eyestripe against the white throat and cheek.<ref name=mahoney1981/> They jump from the breeding cliffs at 20–21 days old, long before being fully fledged, and are cared for by the male parent at sea.<ref name = mullarney1999 />

The common murre has a variety of calls, including a soft purring noise, but the main call of the adults, often deafening at large colonies, is a growling "murrrr"; the chicks have a food-begging call, a high-pitched whistle "willee", with considerable carrying power.
<gallery>
Winter uria aalge.jpg|Adult in winter [[plumage]], [[Germany]]
Guillemot (Uria aalge) in flight.jpg|in flight off [[Skomer Island]]
Guillemot (Uria aalge) mature, on water.jpg|Mature 'bridled' bird (white eye ring)
</gallery>

===Flight===
The common murre flies with fast wing beats and has a flight speed of {{convert|80|km/h|mph|0|abbr=on}}.<ref name=vaughn1937>Vaughn (1937)</ref> Groups of birds are often seen flying together in a line just above the sea surface.<ref name = mullarney1999 /> However, a high [[wing loading]] of 2&nbsp;g/cm<sup>2</sup><ref name=livezey1988>Livezey (1988)</ref> means that this species is not very agile and take-off is difficult.<ref name=bedard1985>Bédard (1985)</ref> Common murres become flightless for 45–60 days while moulting their primary feathers.<ref name=birkheadtaylor1977>Birkhead & Taylor (1977)</ref> The sound of the wing beats of the murres are often described as similar to a helicopter.

===Diving===
[[File:Lomvia troile 53.jpg|thumb|Skeleton]]
The common murre is a [[Seabird#Pursuit diving|pursuit-diver]] that forages for food by swimming underwater using its wings for propulsion. Dives usually last less than one minute, but the bird swims underwater for distances of over {{convert|30|m|ft|-1|abbr=on}} on a regular basis. Diving depths up to {{convert|180|m|ft|-1|abbr=on}} have been recorded,<ref name ="Piatt"/> and birds can remain underwater for a couple of minutes.