GREAT BLACK-BACKED GULL. 



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occasionally pale brown. The spots are seldom much larger than a pea, 

 often very irregular in shape, sometimes elongated into streaks, and, as a 

 rule, evenly, but sparingly, distributed over the surface, though it is not 

 uncommon to find eggs where they are more abundant on the large end. 

 The surface-spots are dark brown, and the underlying spots brownish grey. 

 The eggs vary in length from 3' 2 to 3-0 inch, and in breadth from 2'2 to 

 2-0 inch. The eggs of the Great Black-backed Gull are on KG. average 

 larger than those of any other British Gull ; but small examples are indis- 

 tinguishable from those of the Glaucous Gull and from large examples of 

 the Herring- Gull. 



At the nest the Great Black-backed Gull is a wary bird, and seldom 

 allows itself to be approached within shot, unless it has young. Its notes 

 are loud and harsh, almost as hoarse and quite as unmusical as those of 

 the Raven. Its alarm-note might be represented by the syllable kyaouk, 

 and its call-notes as ag, ag, ag. In winter these birds often congregate 

 where fishing-operations are being carried on. 



The Great Black-backed Gull is about twice the weight of the Lesser 

 Black-backed Gull, but differs from it very slightly in colour. The 

 mantle is darker, the legs and feet are flesh-colour instead of yellow, but 

 the colour of the bill, irides, and orbits is the same in both species. So 

 far as is known, the changes of its plumage are the same as those of the 

 Lesser Black -backed Gull. 



