Migrations of Bewick’s Swan (Cygnus bewickii): New Data on Tagging the Migration Routes, Stopovers, and Wintering Sites

Аннотация

The migration corridors of Bewick’s swan, which inhabits the Yamalo-Nenets Autonomous District, were identified in 2015–2017 using GPS-GMS transmitters. It was shown that even the individuals that inhabit the same region widely used different wintering sites. The birds that nest and molt in southern Yamal (Baydaratskaya Bay) were found to migrate through two corridors: the eastern corridor that leads to southeastern China and the western one that leads to the Caspian Sea, the Evros River delta, countries of Central and Middle Asia, and northwestern China. Fourteen key stopover sites were revealed. We explain the appearance of new Asian and European wintering sites by the general increase in the species’ numbers and believe that the decrease in the size of the Northern European population that has been observed since the mid-1990s is due to a loss of natural habitats. We have shown for the first time that the wintering range of Bewick’s swan with the revealed Asian wintering sites being taken into account is quite large. As the climate changes, some stopover sites can be used as wintering sites, which may lead to an even greater expansion of the wintering range of the species in the future.