POMATOKHINE SKUA 459 



as far as Walvisch Bay. Eastward this species has been 

 obtained in Burmah and Japan ; westward in California and 

 Peru, while it has also been recorded in the Southern Hemi- 

 sphere from North Australia (Saunders). 



DESCRIPTIVE CHARACTERS. 



PLUMAGE. 1 Adult male nuptial. Front and top of head, 

 black ; acuminate neck-feathers, white, edged with light 

 yellow ; lower neck, blackish ; back, wings, and tail, brown, 

 the two central twisted tail-feathers being four inches longer 

 than the rest ; breast and upper abdomen, dull white ; lower 

 abdomen and under wing-coverts, brown. 



Adult female nuptial. Similar to the male plumage. 



Adult winter, male and female. Similar to the nuptial 

 plumage, but the feathers of the flanks, upper and under 

 tail-coverts, have a tendency to exhibit striations in adult 

 birds, not quite mature (Saunders, Cat. Birds Brit. Mus., 

 vol. xxv, p. 326). 



Immature, male and female. Brown, mottled and barred 

 with rufous-buff and black ; the markings on the breast and 

 abdomen vary gradually from distinct striations to an almost 

 uniform brown ; central tail-feathers at first not elongated. 

 The mature plumage is very gradually assumed. 



BEAK. Horn-colour. 



FEET. Brownish. 



IRIDES. Brown. 



AVERAGE MEASUREMENTS. 



TOTAL LENGTH 21 in. 



WING 14-25 



BEAK 1*75 



TARSO-METATARSUS ... ... 2 ,, 



EGG ... 2-6 X 1-8 in. 



1 Dimorphism, also melanism, occur in the plumage of this Skua. 



