BRITAIN'S BIRDS AND THEIR NESTS. 29 



are found. Partly because the name 'Richardson's Skua' 

 rightly belongs only to the dark 'phase,' and partly for 

 the sake of brevity, the name 'Arctic Skua' is now exten- 

 sively used, although it has no special appropriateness. 



The Arctic Skua nests in small numbers on the most 

 northerly parts of the Scottish mainland, and has colonies 

 on the Hebrides, on the Orkneys, and especially on the 

 Shetlands. It is not until the end of May that the eggs 

 are laid. These are two in number, and have dark- 

 brown blotches on a ground varying from chocolate to 

 light-greenish brown. The nest is a mere hollow on the 

 open moor or bog, and is rarely lined. 



The chick is covered with dark -brown down, while 

 birds in immature plumage lack the elongated tail- 

 feathers, and have, in the light phase, dark bars on 

 the under-parts. 



THE GREAT SKUA 



(Megalestris catarrhactes). 



The Great Skua is much less common than the Arctic 

 Skua. It appears to be most numerous on this side 

 of the Atlantic, where its chief haunts are off the 

 Iceland coast. It is also found in small numbers 

 in the Faroes and in the Shetland group. In the 

 latter it was formerly protected, because it drove away 

 eagles from the moors it nested on, and was therefore 

 considered a useful bird by the shepherds. In more 

 recent times the ravages of collectors reduced its numbers; 

 but this decrease was checked by the introduction of 

 protection by the proprietors of Unst and Foula, the 

 only isles on which it nested. The 'Bonxie,' as it is 

 called there, is therefore again on the increase, and new 



