Greater Scaup

Overview

The greater scaup (Aythya marila), just scaup in Europe or, colloquially, "bluebill" in North America, is a mid-sized diving duck, larger than the closely related lesser scaup and tufted duck. It spends the summer months breeding in Iceland, east across Scandinavia, northern Russia and Siberia, Alaska, and northern Canada. During the winter, it migrates south to the coasts of Europe, eastern Asia, and North America.
Male greater scaup average slightly larger than the females but with much overlap; they have a light blue-grey bill and yellow eyes.

Summary from Wikipedia, available under CC BY-SA 4.0.