Female teal are always a challenge, and at this time of year with males looking very female-like, it only gets more confusing. First off, we need to be able to separate the teals from the other ducks. They are dabbling duck and not a diver (no tails in the water) so they tend to ride higher on the water. Teal are small dabblers who fly very fast and have correspondingly fast wing beats due to their size and speed. Now that you picked out the teal, you are left with very similar small brown ducks, but are they green-winged, blue-winged, or cinnamon teal? The easiest one to pick out from the bunch is the green-winged teal. She has vanilla sides to her tail and is quite small billed. That leaves cinnamon and blue-winged teals. You can differentiate these two with head patterns and bills. The female blue-winged teal has a fairly prominent eye line which the cinnamon lacks. Also, cinnamon teal are the northern shoveler of the teal, they have a very large and shovel-like bill. The bill of the blue-winged teal is nicely proportioned, more like a mallard or gadwall in scale.