Green-winged Teal are very small ducks. They have short, blocky bodies and their tails sit high out of the water. The head is large, the neck is short, and the bill is relatively small. Adult males have grayish bodies with a narrow white vertical stripe extending from the waterline to the shoulder. In good light, their dark heads are cinnamon with a wide green swoop from the eye to the back of the neck. Females are brown with a yellowish streak along the tail. Both sexes have green wing patches in the secondaries (speculum), but these may be hidden when not in flight. https://www.allaboutbirds.org/guide/Green-winged_Teal/id