Birds in Bulgaria

L 41-49 cm, WS 112-124 cm. Vagrant from N America. Numerous records annually in Britain & Ireland.
IDENTIFICATION: Three age-groups (see p. 168). Resembles Common Gull, but slightly larger, heavier-bodied, and has thicker bill. - Adult: Clearcut, broad black bill-band (beware sometimes obvious band on ad. winter or 2nd-year Common); yellow iris (brown on Common); paler grey upperparts (similar to Black-headed); faint tertial-crescent (prominent on Common); and smaller ‘mirror’. - 1st-year: Told from Common Gull by paler grey upperparts and midwing-panel, often a few obvious dark crescents among scapulars (unmarked or with only faint shaft streaks on Common), narrower pale tips to tertials, and more variegated tail pattern (broad band on white tail on Common). - 2nd-year: Like adult, but has more black on outer wing; white primary tips and ‘mirror’ (if any) smaller, and often greenish-yellow or greyish bill-base and legs; commonly has variable tail-band (usually lacking on Common). Beware that immature Herring Gull can provide easy pitfall if actually much heavier and longer bill and much larger size are not apparent (e.g. on lone bird); 2nd-year Herring resembles 1st-year Ring-billed, but tertials and coverts more mottled or barred (rather solidly dark-centred on Ring-billed), underwing rather uniformly dusky (neatly dark-flecked, and secondary bar showing through, on Ring-billed), and tail more extensively dark; 3rd-year Herring resembles 2nd-year Ring-billed, but wing and tail patterns less neat, and legs pink. - Has habit of walking about a lot. Also, adults and 2nd-winter birds appear to have remarkably loose plumage.
VOICE: Like Herring Gull’s but higher-pitched and nasal.