Green-winged Teal

Overview

The Eurasian teal (Anas crecca), common teal, or Eurasian green-winged teal is a common and widespread duck that breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal is often called simply the teal due to being the only one of these small dabbling ducks in much of its range. The bird gives its name to the blue-green colour teal.
It is a highly gregarious duck outside the breeding season and can form large flocks.

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