Birds in Bulgaria

L 35-39 cm, WS 86-99 cm. Common colonial breeder at lakes in vast reedbeds or marshy areas, also on ponds near coasts. Migratory in far north, retreating in winter from ice. Abundant feeder on ploughed fields and in towns. Not shy.
IDENTIFICATION: Two age-groups (see p. 168). In flight, told instantly from other common gulls by white leading edge to outer wing; this is its best field mark, often being visible at extremely long range. Similar wing pattern shared only by Slender-billed Gull and vagrant Bonaparte’s Gull; see also Grey-headed Gull (p. 381). Also note: obvious blackish area bordering white leading edge of underwing; pointed (rather tern-like) wings; and proportionately smaller head, longer neck and shorter tail: these all add to distinctive appearance compared with other common gulls. When standing, also told by combination of small size, head pattern (hood or dark ear-spot) and (on adult) reddish bill and legs. - Adult summer: Dark brown hood (often looks black) and dark, dull red bill and legs. - Adult winter: Bold dark earspot and red or brown-red legs and bill, latter with dark tip. - Juvenile (Jun- Sep): Looks strikingly ‘different’, having extensive ginger-brown upperparts and head markings, brown wing markings, black tail-band, and yellowishflesh legs and bill, latter with a dark tip. - 1st-winter: Juvenile wings, tail, and bill and leg colour retained, but head and body like adult winter. - 1stsummer: Like 1st-winter, but many acquire partial hood (at times full hood like ad. summer); brown on wings often faded and much reduced in extent (look for brown-centred tertials); and bill-base and legs more orange-red. VOICE: Noisy at colonies and when feeding in flock; the noise from large colonies in spring can be earsplitting, also at night. Common calls are a strident, downslurred, single or repeated ‘krreearr’, with many variations, and short, sharp ‘kek’ or ‘kekekek’. Slender-billed Gull Larus genei V*** (Дългоклюна чайка) L 37-42 cm, WS 90-102 cm. Habitat and habits much as Black-headed Gull, but more coastal outside breeding season. Rather scarce even in Mediterranean breeding areas, where much rarer than Blackheaded. Vagrant to S Britain. IDENTIFICATION: Mainly two age-groups (see p. 168). A little larger than Black-headed Gull, which it closely resembles in wing pattern and general appearance, but head white (lacks hood) in summer; has only faint ear-spot, if any, in winter; and has usually obvious yellowish or whitish iris (however, can look dark-eyed depending on light; Black-headed Gull always dark-eyed). Also very important for identification is its peculiar head-and-bill shape, produced jointly by longer (but actually not more slender) bill, more elongated forehead, and very long neck when fully extended; beware that Black-headed can give a rather similar impression (but never quite so exaggeratedly), so important to check other differences carefully to avoid misidentification. Legs comparatively long. Adult summer differs further in: usually strong pink wash on underparts; and darker red bill (often looking blackish) and legs. Adult winter has less or no pink, has a pale grey ear-spot (if any), and less dark red bill and legs. In addition to the structural differences from Black-headed, 1st-year has usually paler brown wing markings; paler ear-spot (if any); paler yellowish-brown or orange-flesh bill and legs, and bill with dark tip much smaller or lacking. - Some 2nd-year birds told by dark-centred tertials.
VOICE: Vaguely recalling Black-headed’s, but the rolling call is a lower, drier and harder ‘krerrr’ with a somewhat strained voice. At breeding site some low, gruff, nasal calls.