Goosanders are large freshwater diving ducks with long, narrow, serrated red bills; part of the "Sawbill" family. The male breeding plumage is white with black back and (smooth) head with green sheen.
The female Goosander with grey body and red-brown untidy head is similar to but larger than the related female red-breasted merganser; the latter doesn't have a white chin like the Goosander.
Male in eclipse plumage looks like female
Goosander with Mallard drake