A very small, brightly patterned duck, the Green-winged Teal prefers shallow ponds with lots of emergent vegetation. Along the coast, it prefers tidal creeks, mudflats, and marshes to more open water.
The American and Eurasian forms of the Green-winged Teal were formerly considered different species. The Eurasian teal differ from the American by lacking the vertical white shoulder stripe and having a horizontal white stripe along the back instead. Eurasian teal show up casually each year along both the Pacific and Atlantic coasts.
It was considered conspecific with the Common Teal for some time, and the issue is still being reviewed by the American Ornithologists' Union.
A group of teal has many collective nouns, including a "coil", "dopping", "knob", "paddling", and "spring" of teal.