Slender-billed Gull (Larus genei)
spanwidth min.: 100 cm
spanwidth max.: 110 cm
size min.: 42 cm
size max.: 44 cm
incubation min.: 21 days
incubation max.: 23 days
fledging min.: 0 days
fledging max.: 0 days
eggs min.: 2
eggs max.: 3
Distinctive shape, with long sloping forehead, long slightly drooping bill, and long legs. Head, neck, rump and tail white. Back and upperwings grey. Conspicuous white leading edge to wing, as outer five primaries mainly white, with black tips. Underparts white, with rosy bloom on breast and belly in fresh plumage. bill and legs dark red to blackish red. Iris yellowish white, with red eye-ring. Readily distinguished from L. ridibundus by more angular profile, with smaller head, longer bill and flat-sloping forehead.
Breeds on coasts of Mediterranian, Black and Caspian Seas and Persian Gulf, and at inland seas and steppe lakes in E Europe to C Asia. Utilizes islands, sand spits and beaches, or meadows, grassland, brackish or freshwater marshes of broad river deltas, occasionally in the marine littoral sone. Almost entirely coastal outside breeding season, feeding in shallow inshore waters and at salt-pans, usually avoid harbours.
Larus genei breeds locally in coastal areas of the Mediterranean and Black Seas and in Turkey, with Europe accounting for less than half of its global breeding range. Its European breeding population is relatively small (<56,000 pairs), but increased substantially between 1970-1990. Although the species declined in Russia during 1990-2000, it was stable or increased elsewhere in Europe, and hence remained stable overall. Nevertheless, more than 90% of the European breeding population occurs at just 10 sites.
Mainly fish, make up 50% of diet, also insects and marine invertebrates, captured alive and scavenged. Vegetable matter also important. Engages in aerial dipping to surface, plunging from about one meter, surface dipping and upending. Feeds in intertidal zone, probing in mud with bill. Aerial foraging on swarming insects noted. Scavenges far less than most gulls, hence usually does not congregate near villages, but in winter joins other gulls at sewage outfalls.
This species has a large range, with an estimated global Extent of Occurrence of 100,000-1,000,000 km². It has a large global population estimated to be 300,000-410,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]
Breeding from March to May. Colonies of tens to thousands of pairs, often with terns. Preferentially selects open mud. Nests closely packed. Clutch size 2-3 eggs, incubation 22 days. Chick pale grey to pale buff, variably patterned with dark brown or black spots on head and upperparts, with whitish breast and belly. First breeding at 2-3 years.
Resident or making limited dispersals in southern breeding areas (West Africa; Persian Gulf to Pakistan), but mainly migratory in FSU and eastern Mediterranean. Winter quarters extend south to southern end of Red Sea and north-west coasts of Indian Ocean, with some stragglers further south. In western Mediterranean, main known wintering area Tunisia.