The blue-winged teal is apparently one of the most common ducks in the Caribbean, where they are a non-breeding winter resident. Until a few days ago, I had never seen them in their breeding plumage, but there was a big flock on the Airport Pond in Grand Case. In breeding plumage, the males have a black head with white stripes. Their non-breeding plumage looks like the females on the left of this photo, basically plain brown.