Thursday, April 6, 2017

Lesser Black-backed Gull

Visitors from Europe

Lesser Black-backed Gull [Internet Photo]
 The Lesser Black-backed Gull (Larus fucus) is a visitor from Northern Europe which is seen in our area fairly frequently at this time of year.  A flock has moved up the Saint John River this week.

This species was first reported from Grand Manan in 1968 and 1975.  Since then it has gradually become more common, now found annually along the Bay of Fundy and up the Saint John River as far as Fredericton.  It is usually seen between March and May and then between September and November.

Lesser Black-backed Gull
The Lesser Black-backed Gull is one of the larger gulls, but smaller than the Herring or the Great Black-backed Gull.  It is 54-64 cm (21"-25") in length compared to the Herring Gull which is 56-69 cm (22"-27") and the Great Black-backed Gull which is 64-79 cm (25"-31") in length.  To identify this species you have to distinguish it from the Great Black-backed Gull.  It is smaller as the numbers above indicate.  Its back or mantle is often more grayish black than the pure black back of the Great Black-backed Gull, its head is smaller and the beak is shorter and less robust.  Its dark wings show one or two white spots on the outer primaries.  It has a clear lemon yellow iris with a reddish orbital ring.  Its legs are yellow or orange.  The Great Black-backed Gull has a very large beak, an olive to pale-yellow eye and pink legs.  

Lesser Black-backed Gull
The photo above shows a Lesser sleeping with an adult Great Black-backed Gull behind.  Note the size difference.  The photo was taken in poor light so the leg colours are not discernible.  

Lesser Black-backed Gull
The photo above shows the yellow legs and the size comparison with the Herring Gulls and the single Great Black-backed Gull with which it is grouped.

The Lesser Black-backed Gull breeds in western Greenland and appears to be a non-breeder in this area.  They like to associate with Herring Gulls and prefer the same feeding areas:  beaches, dumps, fishing harbours, lakes, parking lots, and intertidal waters.  It often feeds offshore over shelf areas.

Yesterday, April 5, a large group of these gulls was seen at Fredericton where they were associating with Herring and Great Black-backed Gulls.  Twenty-two were counted with the likelihood of many more out of identification range.  This is an unusually large number for this species.  Obviously it was a migrating flock.  They were mostly all adults.  It is hard to believe these birds are non-breeders.  I wonder if they were headed to a breeding area we don't know about.  An exciting find and a beautiful species to observe.

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