THE GREAT SKUA. 



77 



STERCORARIUS SKUA 



461. Stercorarius skua skua (Briinn.)— THE GREAT SKUA. 



Catharacta Skua Briinnich, Orn. Bor., p. 33 (1764— Faeroes and Ice- 



land). 



Stercorarius catarrhactes (Linnaeus), Yarrell, in, p. 662. 



Megalestris catarrhactes (Linnaeus), Saunders, p. 687. 



Description. — Adult male and female. — Fore-head and crown dark 

 brown, distal portions of feathers with broad central streaks (not 

 very prominent) of pale rufous-brown (often a few white feathers on 

 head) ; feathers of back and sides of neck lanceolate, and dark 

 brown with prominent straw-yellow median streaks ; mantle, 

 scapulars and upper tail-coverts dark brown, distal portions of 

 feathers with broad central streaks of rufous, centre of tips paler 

 and becoming whitish when worn ; back and rump same but rufous 

 and pale tips less conspicuous ; lores, round eyes and chin more 

 uniform dark brown, but feathers more or less tipped yellow -buff ; 

 throat streaked and marked rufous and pale buff but not so 

 prominently as sides of neck ; rest of under-parts grey-brown 

 mottled rufous and 

 feathers of flanks 

 and under tail - 

 coverts with more 

 prominent central 

 tips of pale buff 

 and rufous ; axil- 

 laries and under 

 wing - coverts dark 

 brown, feathers with 

 varying amount of 

 rufous at tips ; tail 

 black-brown, white 

 at extreme base con- 

 cealed by coverts ; primaries black-brown, white at base (on outer 5 

 feathers 30-60 mm. beyond coverts and making larger white patch 

 on under-wing), in outer (2nd) primary outer web only white at 

 extreme base which is almost concealed by coverts, four inner 

 primaries and secondaries black-brown with concealed basal part 

 of feathers white, shafts of primaries whitish-straw almost to tips 

 and those of secondaries on basal two-thirds ; primary-coverts, 

 black-brown ; rest of wing-coverts as upper-parts but greater with 

 only small rufous and pale central tips. This plumage is probably 

 attained by a body-moult early in year, but no birds from Jan. to 

 March are available. Winter. — One adult (Dec.) is moulting remiges. 

 and wing-coverts and body-moult is nearly complete, while others 

 from June to Sept. are moulting on body but not wings or tail. 

 New feathers of neck are rounded and brown without straw- 

 coloured median streaks, and there is no yellow-buff on feathers of 



The Great Skua (Stercorarius s. skua)* 



