786 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



measured). $ wing 305-322, tail : (ad.) central 170-205, outer 

 55-85 shorter, (juv.) central 110-136, outer 10-18 shorter ; bill 

 27-30. Primaries : 1st narrow and about two-thirds primary- 

 coverts, 2nd longest, 3rd 5-15 mm. shorter, 4th 20-30 shorter, 5th 

 40-50 shorter ; outer web of 2nd narrow. Tail as in Great Skua 

 but central pair tapering to a point, except in juvenile which has 

 these feathers abruptly pointed. Rest of structure as Great 

 Skua but bill comparatively wide at base and tip not so abruptly 

 decurved. 



Soft parts. — Bill (ad.) blackish-brown, tip black, (juv.) bluish- 

 grey, darker at tip ; legs and feet (ad.) black, (juv.) bluish-grey with 

 distal half of webs black ; iris dark brown. 



Characters. — Smaller than Pomatorhine and central tail-feathers 

 at all ages more sharply pointed. For distinctions of Long-tailed 

 Skua see under that species. 



Field -characters. — In size much inferior to Great Skua, but flight 

 more graceful, though excelled in this respect by Long-tailed Skua. 

 Dark colouring of upper surface, and in some birds of breast also, 

 easy hawk-like flight and very characteristic wedge-shaped tail 

 with two long straight projecting feathers quite different from very 

 elongated pointed streamers of Long-tailed Skua or twisted tail- 

 feathers of Pomatorhine, serve readily to identify adults. Cry is 

 also quite different from those of Gulls, a wailing " Tee-ow, yee-ow," 

 but there is also a conversational " gack, gack." Juveniles of the 

 smaller Skuas are difficult to identify in the field. (F. C.R.J.) 



Breeding-habits. — Breeds in colonies on moorlands, tundra, and 

 in far north on shingle. Some of these colonies are of considerable 

 size, but isolated pairs may also be met with. Nest. — Little more 

 than a neatly rounded depression in moss, grass or heather, some- 

 times lined with a little grass or roots of arctic willow. Eggs. — 

 Xormally 2, but occasionally 3, while 4 have once been recorded, 

 greenish, olive or umber-brown, quite exceptionally light blue in 

 ground, with spots and a blotch or two of dark umber-brown. 

 Average of 100 eggs, 57.05x40.93. Max.: 63.1 X 43.7 and 59x44.3. 

 Min. : 49x39.1 and 59.6x37.2 mm. Breeding -season. — End May 

 and early June, but occasionally eggs may be found as late as July 

 and even August in far north. Incubation, — By both sexes. Period 

 24 days (Faber) to 28 (?). Single brooded. 



Food. — Obtains part of its food by pursuit of Terns and smaller 

 Gulls : has been known to attack and kill lambs : will pursue and 

 kill wounded birds, and has been seen to kill Purple Sandpiper and 

 Lapland Bunting. Devours eggs of other birds freely (Eider Duck, 

 Ringed Plover, Common Gull, etc.), and also nestlings (Red Grouse,, 

 etc.) : also recorded as capturing fish, worms, insects, including 

 coleoptera (Elater, Harpalus, etc.), diptera (Tipula), odonata^ 

 phryganeidse (Limnophilus), Crustacea and actiniae. Saunders also 

 includes mollusca and Turner says that it eats berries of Empetrum 

 nigrum. 



