Arctic Loon

Gavia arctica (Linnaeus, 1758)

		adult summer immature
2015-07-17 Eastern Kazakhstan 2006-05-31 Kenzharyk village, Karaganda district	© Oleg Belyalov © Maxim Koshkin

Description

Black-throated Diver in breeding plumage has ashy-grey upper-head and neck; mantle is black with purple and green tinge and with rows of white spots; throat and upper part of fore-neck are black with green and purple tinges; there is row of white spots on throat; and white strips on neck-flanks; flanks are black; upperparts including axillaries are white. Bill is black; legs are black in outer parts and bluish-grey in inner ones. Eyes are red-brownish. In winter plumage upperparts are black-brownish; underparts including cheeks and feathers of neck are white; upperhead and rear-neck are grey. Juveniles have plumage as on winter adults, but more dingy. Sizes: wing 290-350 mm, tail 54-62 mm, tarsus 80-83 mm, bill 58-70 mm.

Distribution

Breeding on northern plains, central and eastern areas of Kazakhstan, in the south up to the lower Turgay river, Balkhash lake, Sasykkol and Alakol lakes. Breeds on lakes of Altai mountains (Markakol lake and Yazevoe lake) and on Zaysan lake. Widespread throughout Kazakhstan on migration including Bolshoye Almatinskoye lake (24 May 2002). Wintering in southern Kazakhstan rare: south of Shymkent and in Ile delta.

Biology

Black-throated Diver is rare breeding migrant. Spring occurrence end April – late May. Nesting on large reservoirs with surface vegetation in forest-steppe, steppe and on mountain taiga lakes. Breeds in separate pairs at 0.5-1.5 km from each other. Nest is built along the shores of lakes or on old floating vegetation in reservoirs from dry reed stems and leaves; sometimes eggs laid in shallow hole in wet ground. Clutches 2, rarely 3 eggs in mid-May - end of June. Incubation lasts 28 days. Often a brood consists of only one nestling. Juveniles recorded from end May to mid-September. Autumn migration singly and in flocks of up to 7 birds from second half of September before reservoirs freeze (generally to mid-October – early November).

Subspecies

References

"Птицы Казахстана" том 1. "Наука". Алма-Ата, 1960.
Э.И.Гаврилов. "Фауна и распространение птиц Казахстана". Алматы, 1999.
Gavrilov E. I., Gavrilov A. E. "The Birds of Kazakhstan". Almaty, 2005.