ix YOUTH, MATURITY, AND AGE 291 



the young birds resemble. If the two sexes are alike 

 when mature, the young birds may, as with the Robins, 

 have a distinct plumage of their own ; or, as with the 

 Kingfisher and Jay and many sober-hued birds, young 

 and old may be alike. Still the resemblance is often 

 not exact. When, as in the case of the Dunlin, both 

 sexes put on a distinct and richer dress in spring, it is 

 the old birds in their winter garb that the young 

 resemble. 



The age at which maturity is attained varies much 

 in different species. Our small birds are ready to nest 

 the first spring after their birth. In some cases there 

 is no difference of plumage ; the young swallows 

 arrive later than the old ones, but when they have 

 arrived they are indistinguishable. Gulls, however, do 

 not appear in quite mature plumage till their third or 

 fourth year, or even their fifth — i.e., till the moult at the 

 end of their fifth summer. The young Lesser Black- 

 backed Gull keeps his first plumage till the summer 

 following. Then comes a moult, after which we find 

 him still brown but paler than in his first year. At the 

 end of his third summer his colour becomes an ashen 

 gray, and the tail is in some specimens white, in others 

 mottled. None of the primary wing-feathers, or, at 

 any rate, only one of them, has a white spot or 

 " mirror." The moult after his fourth summer brings 

 him to the plumage of his maturity — back and wings 

 black, breast white, head white with dusky streaks 

 that will pass away and leave pure white in spring. A 

 Gannet, which may be described as grown up, has not a 

 single black feather except the primaries ; all the rest 

 of him is white except the fine cream-coloured head 



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