384 PHALACROCORAX CARBO. 



Length to end of tail 35 inches ; extent of wings 58 ; 

 wing from flexure 18^^ ; tail 6; bill along the ridge 2; tarsus 

 2 ; outer toe and claw 4-^. 



Variations. — Great differences are observed as to size in 

 adult birds of the same sex, some individuals being so much 

 smaller as at first to seem of another species. Unless in the 

 tint of the feathers of the back and wings, which may be 

 lighter or darker, sometimes approaching to grey, old birds 

 do not appear to vary much. 



Changes of Plumage. — The general moult takes place 

 from the middle of summer to September. The plumage 

 continues as described above until March or April, when a 

 partial change takes place, consisting chiefly of the production 

 of numerous slender white feathers on the head and neck, as 

 well as on the thighs, together with an elongated crest of 

 linear feathers. As the summer advances, the bronzed tints 

 of the upper parts become of a paler brown. 



Male in Summer. — The bare parts at the base of the 

 bill are of a purer yellow. There is an elongated longitudinal 

 crest of greenish-black feathers on the head and nape ; the 

 band on the throat and cheeks is pure white ; among the 

 feathers of the head and upper neck are numerous linear 

 loose-edged white feathers, giving those parts a hoary appear- 

 ance ; and over each thigh is a large patch of similar more 

 elongated white feathers. 



Female in Summer. — The female is similar to the male. 



Habits. — The Great Cormorant occurs in considerable 

 numbers, here and there, on all our rocky coasts, frequenting 

 bold headlands, high cliffs, and rugged insular crags. It 

 generally keeps apart from the Crested Cormorant, and, when 

 the two species occur in the same locality, assumes a more 

 elevated station, the other betaking itself to the caves, or 

 perching on the lower shelves. At certain states of the tide, 

 chiefly, I think, about low Avater, and not at any particular 



