THE LIFE-HISTORY OF BIRDS 275 



immature and adult liveries, and consequently, wherever this 

 livery is assumed early, all trace of the age of the wearer is 

 lost after the first autumn. When, as so often happens, the 

 young assume the livery of the parents at once, e.g., Corvids 

 and Kingfisher, they can only be distinguished by the lack of 

 gloss and brilliancy. Thus, although for general purposes we 

 assume that the characteristic full plumage is a sign that adult 

 life has been attained, this is not necessarily always the case. 

 Many of the Gulls, for example, take at least three years to 

 attain the full dress of the species, the change from the " im- 

 mature" to the mature dress being made by almost insensible 

 gradations ; similarly, the birds of prey are known to take 

 several years in arriving at maturity. 



Sexual maturity can no more be regarded as an index of 

 physical maturity than the plumage, for with birds, as with 

 many other animals, reproduction often begins before the fully 

 adult condition has been reached, e.g.. Golden Oriole, Black 

 Redstart, Night-heron, Tantalus Ibis. 



Maturity attained, in a large number of species two sharply 

 distinct liveries are worn during each year, and these are 

 generally, but not always happily, described as the " summer " 

 and "winter" plumages. More correctly the "summer" dress 

 is now designated by many the "nuptial" dress, since it is 

 assumed prior to, and worn during the breeding season. In 

 cases of this nature both sexes alike very commonly assume 

 these wedding garmer ts, though the male is usually distinguish- 

 able by the greater vividness of his colours ; in many instances, 

 however, only the males don this distinctive dress. The 

 Wading-birds present instances of both kinds. Thus in the 

 Dunlins, Knots, Godwits and the Grey and Golden Plovers, and 

 the kindred Auks, Guillemots and Puffins, both sexes put on 

 this characteristic dress, while in the case of the Ruff {Machetes 

 pugnax) only the male is so distinguished. Among the Gulls, 

 however, many species adopt no special change. But the 

 Plover tribe, it is hardly necessary to say, are by no means 

 the only birds which assume a special nuptial plumage, and 

 there is neither reason nor space to enumerate all those which 

 display this phenomenon. 



But a very striking case of this sequence of plumages is 

 seen in the Scarlet Tanager {Pyranga erythrumelas), wherein 



