Adult male is small with a dark gray head with a white crescent, a light blue patch on the forewing, and a greenish speculum (wing patch). Female is brown with yellow legs, a dark eye line, and a whitish spot between the bill and the eye. The female’s blue wing patches, gray-brown speculum, and undertail coverts that are darker and heavily spotted separate it from the female green-winged teal, which lacks the blue wing patch, has a green speculum, lacks the white between bill and eye, and has whitish undertail coverts. Males make high peeps, females high-pitched quacks.
Similar species: The cinnamon teal is a rare (west) or casual (east) migrant and accidental winter resident in Missouri. Males are almost entirely cinnamon colored. Females are browner than female blue-winged teal and lack the dark eye line and white spot between bill and eye.