Common Murre

Common Murre - A Pelagic Bird

Common Murre in Breeding Plumage

With reports of sightings of Thick-billed Murres seen in the last two weeks, it is time to post about our Common Murre.  There is a post on the Thick-billed Murre elsewhere on this blog.  (Use the search engine on the blog to find it).

Murres are Alcids (family Alcidae).  Of the 22 species in this family in North America we have 6.  Alcids are football-shaped oceanic birds generally black and white in colour.  The only time they come to land is for nesting.  They nest in colonies and the juveniles leave the nest before fully developed, maturing at sea.  All members of this family pursue food by diving usually deep into the ocean.  They propel themselves under water with their wings and the feet are used only for steering.  Their wings are relatively small making air-flying cumbersome.  Takeoff is difficult and some cannot take off from land.  

The Common Murre has clean black and white plumage.  When out of the water they walk upright putting their weight on their horizontal tarsi, looking somewhat like a penguin.  In breeding plumage they are brownish black above and white below with sparse dark streaking on the flanks.  The head profile is nearly a straight line.  The bill is long and dagger-like.  The trailing edge of the inner wing is white giving a single wing bar.  The neck is slender and is contracted in flight.  The underwing is white with much brown mottling.  The legs, feet and bill are black.  The shape of the black line around the neck makes a smooth U-shape in front.  This is a distinguishing feature.  (Note the Thick-billed Murre has an upside-down V-shape here.)  The eyes of the Common Murre are dark brown.  Occasionally in breeding plumage there is a bridled adult morph with a prominent white spectacle as seen in the photo below.

Common Murre Bridled Morph

The winter plumage is similar to the breeding plumage except that its throat, sides of neck, nape and face are white with a dark streak extending from the back of the eye to the nape.  See photo below for a winter plumage adult.

Common Murre in Winter Plumage [Internet Photo]

The Common Murre breeds along the Arctic coast of Alaska south to California and in the east from Labrador south to Massachusetts.  It is a permanent resident in the Gulf of St. Lawrence and winters in the Bay of Fundy.  

Common Murres nest on rocky ledges.  Using no nesting material,  they lay one white, green, blue or brown speckled egg.  Each egg is unique and the differences are used by the adults to identify their own egg.    Incubation takes 28 to 33 days and is carried out by both adults.  Courtship displays include bowing, billing and preening.  Murres vocalize a lot on the breeding grounds, purring softly.  They also croak, growl and moan.  Displaying males point their heads vertically and make these croaking and growling sounds.  The breeding colony at Cape St. Mary's, NL, can be heard a long distance away with all the sea birds vocalizing.

Murres feed on fish, marine worms, amphipods, shrimp and mollusks.  They forage by diving deep, remaining underwater up to a minute.  They often go 30 metres/100 feet deep and have been recorded to dive 150 metres/500 feet.

Common Murre (left); Thick-billed Murre (right) [Internet Photo]

For the bird watcher the Common Murre needs to be distinguished from the Thick-billed Murre.  The Thick-billed is blacker, has a thicker bill, shows a white line behind the bill and has an upside-down V on the white on the neck line, it being a smooth U on the Common Murre.  They are nearly the same size; Common - 46 cm/18 in; Thick-billed - 43 cm/17 in.

A group of murres is sometimes called a 'fragrance of murres'.  Judging by the smell of the murre/seabird colony at Cape St. Mary's, that is a very good descriptive term!  I smelled it a kilometre away.