The fabled Falcated Duck, Anas falcata, returned in early December to the Colusa National Wildlife Refuge. The Falcated Duck (previously called Falcated Teal) is an Asian species that occasionally wanders to the Aleutians, but rarely to the lower 48, so it's a lifer for many birders. Even in Asia the Falcated is not common, numbering perhaps 100,000 in total population. Like many of our waterfowl they breed in the far north and migrate fairly long distances to the south for the winter. The Falcated is a dabbling duck, in the genus Anas, and has no real close relatives. I've read that it is probably closest to the Gadwall, as suggested here by the shingled breast feathers. The female Falcated's call is said to be very similar to the Gadwall female's.
Here the Falcated Duck is swimming near a male American Wigeon. When we watched these ducks on December 7 it was apparent that the Falcated Duck drake had an interest in a particular American Wigeon hen and somewhat aggressively blocked the approach of any male Wigeons. The photos show that the Falcated has a brownish crown and reddish-brown cheek, and of course a stunning emerald iridescence of extending back from the eye. There is a small white spot at the base of the black bill, and a transverse black stripe on the white neck band. Not that we really need to dwell on field marks, as there really is not other bird remotely like this awesome dabbler.
As we watched, the Falcated turned and swam directly towards the viewing platform, creating a bit of a bow wave. Fortunately the camera has rapid auto-focus, as the scope has limited depth of field as it's almost impossible to keep an approaching subject in sharp focus. Note here how the sickle-shaped tertials hang out and down towards the rear. "Falcated" means "sickle-shaped".
Frontal view shows the neat shingled breast feathers, as well as the tertials and other features mentioned above. When in the California's Central Valley in winter, make time to watch the awesome gathering of waterfowl in other preserves of the Sacramento Wildlife Refuge complex, especially the Sacramento NWP, and the state's Llano Seco unit.