Last weekend on a bike ride, I spotted this unusual looking duck in a canal in my neighborhood. It is unusual because of the green color in the head and face. I emailed Dr. Tetsuo Shimada, a senior researcher at the Miyagi prefecture environmental foundation for an identification. He confirmed my suspicion that it was a hybrid between the common mallard and the spot-billed duck. Spot-billed ducks are one of the most common, year-round water fowl in Osaka. You see them in almost every pond. Mallards interbreed with spot-billed ducks and some think they are one species. It makes sense in that I read the hybrids are fertile, which goes against the idea of distinct species.
This hybrid was with another spot-billed duck (photo below), perhaps a female, so he (green head would indicate a male) seems to be getting along fine with his life. I haven’t seen many mallards in the neighborhood.
Thanks to Dr. Shimada, who I found through his published research on the spot-billed duck. He is currently studying the wintering population of Brant Goose in Sendai. I hope someday to get to that part of Japan.