The distribution and status of Bewick's Swans Cygnus bewickii, Tundra Swans C. columbianus and Whooper Swans C. cygnus in the "Extreme Northeast" of the USSR

Abstract

The distribution, numbers and status of three swan species: Bewick’s, Tundra and Whooper swans, in the ‘Extreme Northeast of Asia ’ are described. The breeding grounds of Bewick’s Swans cover the maritime tundra of the Arctic basin eastwards as far as Kolyuchin Bay in the Chukotka Sea. A total of 1,200 Bewick’s Swans live in the region of which at least 90% are concentrated in the Kolyma Lowlands (over 700 birds) and Chaun Lowlands (over 300 birds). Breeding birds comprise about 23 % of the total number of Bewick's Swans in the breeding grounds each year. It has been established that some pairs of Tundra Swans are breeding in a number of low-lying sections of the sea-coast of eastern Chukotka. The region of supposed sporadic breeding extends from the Vankarem Lowland to Krest Bay. There are no data concerning the status of the Tundra Swan but intensive economic development of the breeding sites causes concern for the fate of this species. The Whooper Swan is widely distributed in the taiga zone of the Extreme Northeast, but data on its breeding status and population size are very limited. According to preliminary estimates about 2,200 Whooper Swans are in the region. Two main migration routes have been monitored. Birds which settle in the Anadyr-Penzhina Lowland fly across Kamchatka and the Kurile Islands. The remaining birds follow the western Sea of Okhotsk.