GANNET. ' 357 



brooding bird covers it with one or both feet before lowering its 

 body upon it ; this extraordinary method of incubation was 

 long treated as a myth. Both birds build and incubate ; incuba- 

 tion lasts six weeks. The eggs are laid from March onward, a 

 second egg being laid if the first is destroyed. When first 

 hatched the dark slate young are blind and naked, but patches 

 of down soon appear, and grow in volume into a thick woolly 

 covering (Plate 156). It feeds by plunging its head and often 

 most of its body into the huge gape of the parent, groping for 

 disgorged fish. In a few weeks feathers show, at first on the 

 back, and by degrees replace the down, until, in first plumage, 

 the bird is dark brown, speckled with white. After remaining 

 three months on the rocks they depart in this dress. Storm- 

 driven Gannets in this plumage are not uncommon inland, and 

 occasionally, after a gale, a fagged and starving mature bird is 

 picked up in a field or more unlikely situation miles from the 

 sea. When twelve months old the head and neck are mottled 

 with white and the under parts lose most of their brown colour. 

 After the second autumn moult the entire head is white and 

 patches show on the upper parts. After the third and fourth 

 moults the dark colour is gradually replaced by white. Though 

 in captivity a bird has attained full mature dress in two and a 

 half years, the usual time appears to be the fourth year, though 

 Seebohm and Saunders say after the fifth moult. There may be 

 irregularity in the duration of immaturity, but individual varia- 

 tion in the distribution of dark and fight in birds of the same 

 age may have caused confusion. 



The mature bird is white, tinged with buff on the head 

 and neck ; the quills are dark brown. The skin round the eye 

 is dark steel-blue, the bill slate-blue with a horn-coloured tip. 

 The legs are slate-blue, lined with green on the toes and front of 

 the tarsus ; the claws are horn-coloured. The irides are usually 

 described as creamy white, but were distinctly pale yellowish 

 green in a bird I examined immediately after death ; Dresser 



