406 A PRACTICAL HANDBOOK OP BRITISH BIRDS. 



feathers of upper-parts gradually become worn and in tail-feathers 

 soon disappear, dark tips to feathers of under-parts also lessen by 

 wear. 



First summer and second winter* — The juvenile plumage 

 appears to commence to moult about March (Gurney, Gannet, p. 478), 

 and birds apparently completing same moult in Sept. (i.e. 15 

 months old) with outer primaries growing have : head and neck 

 white faintly tinged buff and with a few old brown feathers here 

 and there ; upper -mantle with considerable mixture of pure white 

 feathers, but most brown-black with large white V-shaped tips ; 

 rest of mantle brown-black with smaller white V-shaped tips than 

 in juvenile ; scapulars with only minute white mark at tip ; back 

 and rump with white tips larger but considerably smaller than 

 those in juvenile ; upper tail-coverts much as juvenile ; under- 

 parts white with a few small brown marks on breast ; lower-flanks 

 mostly brown with white central streaks and tips ; axillaries white ; 

 under wing-coverts white or whitish in most, but round edge of 

 wing slate-brown with white tips ; new tail-feathers and wing- 

 feathers as in juvenile ; wing -coverts with small white tips as mantle 

 and innermost secondaries with very small white tips. N.B. — An 

 undated bird is like above, but with uppermost lesser wing-coverts 

 white. 



Second summer and third winter. — Birds apparently 2 years 

 old moulting in July and Sept. have new plumage as follows : 

 crown and neck as adult but pale cream-colour and with a few 

 brownish feathers ; upper-mantle white ; rest of mantle, scapulars, 

 back, and rump mixture of black and white, some feathers wholly 

 white, others wholly black-brown, others parti -coloured ; upper 

 tail-coverts white, but some central ones black-brown ; under- 

 parts white ; under wing-coverts mostly white with some brown 

 along edge of wing ; outermost one or two pairs of tail-feathers 

 white, rest black-brown with white streaks on outer ones and white 

 tips on central ones ; secondaries black-brown some with small 

 white tips, innermost short ones white ; lesser wing-coverts white ; 

 median and greater mixture of white and brown-black and parti- 

 coloured feathers. 



Third summer and fourth winter. — Birds apparently 3 years 

 old moulting in Sept. have heads and neck like adult, but rather 

 paler ; body-plumage as adult but with two or three black scapu- 

 lars ; tail-feathers : outer ones white, rest some white and some 

 black-brown (some of latter new ones growing and in one case with 

 corresponding feathers on each side differently coloured) ; second- 

 aries black-brown with white edges varying in breadth, innermost 

 white ; all wing-coverts white. N.B. — Others on same date as 



* The material available is insufficient to make sure of the sequence and. 

 moults before reaching adult plumage. Spring material is entirely lacking, 

 so it is impossible to say what is the effect of the spring moult and indeed if 

 there is one, but in any case it does not seem to involve the wing- and tail- 

 feathers.— H.F.W. 



