THE MOULTING OF BIRDS. 171 



white plumage of the adult. In the Pelicans the young 

 are naked when first hatched, but soon become clothed 

 in down. Like the Swans they retain their first plumage 

 until their second autumn. Young Cormorants in first 

 plumage are brown above, shading into nearly white on 

 the centre of the belly, and the feathers of the upper 

 parts have broad dark margins. After this plumage is 

 moulted, an intermediate one is assumed, with more 

 metallic gloss above and less white below. The Gannet 

 passes through a series of mottled plumages of black, 

 brown and white, ere it attains its adult dress when it is 

 quite four years old. It is an interesting fact that this 

 bird begins its life in a snow-white garb of down, then 

 passes through parti-coloured plumages to the white 

 dress of maturity. Young owls in the nestling stage of 

 their existence are covered with down. In their first 

 plumage they do not differ very greatly from their 

 parents, but the colours are more dingy, and the 

 markings in many species are not so clearly defined. 



We now reach the fourth and last division, in which 

 the birds may be said to be in a chronic state of moult. 

 In this group we include the Swifts, the Birds of Prey, 

 the Herons, and the Ptarmigan. In addition to the 

 spring and autumn moult, which all these birds undergo, 

 with the exception of the Ptarmigan, all are moulting 

 their quills throughout the year, save perhaps in the 

 breeding season, these feathers dropping out in pairs 



