If it looks like a sandpiper, acts like a sandpiper and flies like a sandpiper it must be a sandpiper, except when it’s a duck. There is only one duck that regularly and artfully pulls off a sandpiper impersonation: the Green-winged Teal.
Green-winged Teal frequently forage on mudflats, busily poking and prodding at the mud, just like a sandpiper. The females are garbed in drab brown similar to many sandpipers and in the late summer and early fall and the males are also mostly or fully brown. Identifying female ducks, particularly small female dabbling ducks, can be a challenge at times, but if you see a small brown duck waddling around on a mudflat, think Green-winged Teal first. The species most likely to be confused with a female Green-winged Teal is a female Blue-winged Teal. Blue-winged Teal occasionally sit on mudflats but rarely actively forage on mud. So if you see a brown teal that seems to be channeling a Dunlin chances are good it is a Green-winged.
If you want to double check the behavior-based identification, look for an oversized head with a blocky shape, short bill, and a distinct pale stripe just below the tail feathers. Other ducks will forage on mud at times, Northern Pintail, Mallards and American Wigeon in particular. But none really appear at home in this environment while Green-winged Teal almost seem to prefer mud to water in many locations.
Green-winged Teal even form flocks that look like a flock of sandpipers. Very tightly packed oval or wedge-shaded bunches that twist and turn with great agility. Unlike sandpiper flocks that seem perfectly in synch, there are usually a few birds at the back of a flock of Green-winged Teal that seem not be getting the message the birds in the front of the flock are sending and are half a twist or turn off the pace. The shorebird-like behavior of Green-winged Teal can simplify the identification of this species and watching this little duck doing its best shorebird impersonation can be highly entertaining!
Cameron Cox currently leads photographic birding tours all over the world. To learn more about these tours or to sign-up for one, please visit the Tropical Birding website.