Somewhat difficult to determine with the muddy head, but I decided I could make out a little bit of yellow in front of the eye. However, the base of the beak seems to be more v shaped than straight across. Given that the trumpeter is rare here, I decided to call this bird a tundra.
The Tundra Swan (Cygnus columbianus) is a small Holarctic swan. The two taxa within it are usually regarded as conspecific, but are also sometimes split into two species, Cygnus bewickii (Bewick's Swan) of the Palaearctic and the Whistling Swan, C. columbianus proper, of the Nearctic. Birds from eastern Russia (roughly east of the Taimyr Peninsula) are sometimes separated as the subspecies C. c. jankowskii, but this is not widely accepted as distinct, most authors including them...
