692 ARCTIC OR Richardson's skua. 



being entirely sooty, while the other has light under-parts ; but 

 where they meet they mate indiscriminately. Both the extreme 

 and intermediate forms are found nesting on our northern islands, 

 the Faeroes, Iceland, the coasts of Scandinavia, Russia, and probably 

 Novaya Zemlya; but the sooty bird has seldom been observed in the 

 Spitsbergen group, and most of the specimens from the far north of 

 America are white-breasted. The dark form predominates towards 

 the southern limit of the bird's breeding-range, whereas the white- 

 breasted race increases in numbers to the northward until it gains 

 the ascendency. As a breeding-species this Skua may be described 

 as circumpolar ; in the cold season it frequents the coasts of Europe 

 down to the Mediterranean, West Africa as far as the Cape of Good 

 Hope, the Persian Gulf and Mekran coast, the North Pacific to 

 California, and the Atlantic to Barbados and even Rio de Janeiro, 

 while it has occurred several times in Tasmania and New Zealand. 



Towards the end of May or early in June the eggs, 2 in number, 

 are laid in a hollow of the moorland moss or grass ; they are of a 

 brownish-green colour, blotched with dark brown: measurements 2*4 

 by I 6 in. The flight of this Skua is rapid, although somewhat devious; 

 and any intrusion upon the breeding-ground is resented by swoops 

 which are directed from behind or sideways ; but although the bird 

 will actually strike with its wing, I have never seen it make a front- 

 attack. The cry is a plaintive inee, sometimes a sharp mee-dwh. 

 This species feeds principally upon fish, obtained by robbing the 

 smaller Gulls, but it also preys upon wounded or disabled birds, is 

 said to plunder the eggs of other sea-fowl, and has been known to 

 pick up worms and molluscs. It does not dive, but has frequently 

 been observed to settle on the water. 



The lowest figure is that of an adult though, but not a very mature 

 example of the intermediate form ; in many, as already observed, 

 the throat and breast are white, and not shaded with brown. The 

 middle bird may be said to belong to the dark race, though more 

 sooty individuals are to be met with. Between the above there is 

 every gradation ; but all the adults have a yellow tinge on the 

 acuminate feathers of the cheeks and neck, and are umber-brown 

 on the upper-parts. Length 20 in. (tail 5, and central pair of 

 feathers often 3 in. longer), wing 13 in. The young bird (at the 

 top) I consider to be the offspring of light-coloured parents ; the 

 progeny of a dark pair being much more .sooty, with merely rufous 

 edges to the upper feathers. 



