English: Great Black-headed Gull, Pallas’s Gull  

Russian: Черноголовый хохотун

Mongolian: Итэлгэн цахлай

German: Fischmowe

French: Goeland ichthyaete

Japanese:  オオズグロカモメ (O-zuguro-kamome)

Body length: 58-67 cm.
Wing span: 146-162 cm.

Is Obviously not a ‘large white-headed gull’ but treated here for easy comparison due to its large size and because non-adults have mainly whitish head. Nests colonially on marshes, like islands etc. in SE Russia. Scarce  but regular in Middle East in winter; vagrant to Europe, with only one record in Britain (in 1859), none in Ireland, but scattered genuine later records in other W and C European countries, north to Sweden. Food fish, crustaceans, insects (also swarming in flight), small mammals etc.

Identification: Four age-groups, but plumage development initially quick as in a tree-year gull. As large as or larger than Herring Gull. But slightly slimmer-bodied and longer-winged, with elongated forehead which accentuates length and heaviness of bill. In flight, slightly slimmer-winged than other large gulls, with deep chest, long head, and large bill giving front-heavy look. Very large size and black hood make adult summer unmistakable, but standing birds in other plumage could easily be overlooked as Caspian Gulls, except for usually obvious dark ‘mask’ and white eye-crescents. Also, important always to bear in mind pitfall of some other large gull with oil-stained head, thus essential to check other diagnostic features described below, especially the distinctive wing and tail patterns.

• Adult: Outer wing mainly white, with black crescent across tip; black-banded yellowish bill (with red towards tip in summer); and yellowish legs.
  
• Juvenile: Scaly brown above; brown breast-sides or breast-band contrasting with white rest of underparts; striking pale grey midwing-panel; underwing-coverts white; broad, clear-cut, black tail-band; pale dark-tipped bill; and greyish or brownish-flesh legs.
  
• 1st winter/1st summer: As juvenile, except adult-like pale grey upperparts, dark hindneck; bill and legs often show some yellowish in 1st summer; 2nd year; Like adult, but much black on outer wing, and thin  black tail-band. 3rd year: Like adult, but more black on wing-tip, and sometimes trace of tail-band.