Birds in Bulgaria

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.