Birds of Britain 



and is blackish on the back, white beneath, and yellowish 

 on the head. It remains in the nest for about three 

 weeks, by which time it is covered on the back and breast 

 with downy feathers and has tiny wing feathers caused, 

 as in the case of the game birds, by the rapid growth of 

 the primary wing coverts. 



At this age the young may be found in the sea, having 

 presumably been carried down by their parents ; they can 

 swim readily, but it is said that unless forcibly made to 

 dive by their parents they remain on the surface. In 

 captivity, however, they dive without hesitation on the 

 least sign of alarm, using both wings and feet, and progress 

 with considerable rapidity under water. 



At the age of about two months the flight feathers 

 proper begin to grow, and then the autumnal moult takes 

 place. 



In summer the adult has the head, neck, chin, throat, 

 and back deep blackish brown, a narrow line from the 

 eye to the culmen white, and the rest of the under parts 

 white. The bill is black and vertically flattened; it has 

 two or more grooves ' near the tip that are whitish. It 

 varies greatly in size, and is much larger in some individuals 

 than in others, this difference being probably due to age. 

 The sexes are alike, and in winter the chin and throat are 

 white. Except in the size of the bill, the young bird 

 resembles the adult after the first moult. Length 17 in.; 

 wing 7*3 in. 



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