GREAT SKUA 



i8i 



of doubt ; still, as the bird is widely distributed in tropical and sub- 

 tropical seas, there is no reason why a straggler should not occasionally 

 be blown to the British shores. 



Great Skua ^^^ Stercorariidai, or second family of the Gaviae, is 

 (Stereorarius represented only by the large prcdaceous gull-like 

 eatarrhaetes). ^'^^^^^' '"^"o^^'"' apparently from their cry of skiii-skui, 

 as skuas. From the Larids they are distinguished 

 by the presence of a bare horny structure — the cere — at the base 

 of the beak, aitd the powerful, strongly curved, sharp claws ; while 

 internally they differ 

 by the much greater 

 length of the pair 

 of blind appendages 

 (cajca) to the lower 

 part of the intestine. 

 In conformity with 

 their habits, the beak 

 of these birds, al- 

 though of a gull-like 

 type, is broader at 

 the base, more arched, 

 and has the tip of its 

 upper half overhang- 

 ing the lower. As 

 in the gulls and terns, 

 the three front -toes 

 are connected to- 

 gether by webs, and 

 the hind-toe is small ; 



while the front surface of the shank of the leg is protected by large 

 transverse shield-like scales. In the long and pointed wings, so admir- 

 ably adapted for a strong swooping flight, the first quill is the longest ; 

 and in the long and rounded tail, which forms an effective rudder, the 

 two middle feathers project beyond the rest to a greater or less degree. 

 Although in several of the species the colouring is very tern-like, in 

 others the whole plumage is sooty. In addition to the internal 

 character already noted, skuas differ from gulls and terns in having 

 only one (in place of two) notch on each side of the lower, or hind, 

 border of the breast-bone, or sternum. 



Skuas are veritable pirates of the gull-tribe, and live by robbing 



GKKAT SKUA. 



