318 



BRITISH BIRDS. 



grey. The eggs vary in length from 2'35 to 2"1 inch, and in breadth from i'7 

 to 1*6 inch. The eggs of the Common Gull are not very easily confused 

 with those of any other British Gull. Only one brood is reared in the 

 year. 



The Common Gull in breeding-plumage may be regarded as a small 

 edition of the Lesser Black-backed Gull ; but the colour of the mantle is 

 slightly paler, the pattern on the primaries is less distinct, and the yellow 

 of the bill, legs, and feet is always more or less suffused with green. After 

 the autumn moult the head and neck are streaked with greyish brown, as 

 they are in its larger ally. After the second autumn moult, which begins 

 very early, the only signs o£ immaturity left are the absence of the white 

 subterminal spot on the primaries, and traces of the bar across the end of 

 the tail. After the first autumn moult the bird only differs from young in 

 first plumage in having a few adult feathers on the back and wing-coverts ; 

 but, with the exceptions above named, the immature feathers are slowly 

 moulted into adult plumage in the following spring during the four months 

 of March to June. Young in first plumage have the greater wing-coverts 

 as in the adult, the rest of the small feathers of the upper parts being brown 

 with pale edges, those of the underparts white with pale brown edges, the 

 tail-feathers with a nearly terminal broad black band, and the bill, legs, and 

 feet are brown. Young in down are greyish buff, mottled with black on 

 the upper parts. 





COMMON GULL. 



