Brewer’s Duck

The Brewer’s Duck is a hybrid between a Mallard and a Gadwall

Although I cannot count it as a new species on my lists, I do believe this bird is worthy of a little attention. The “Brewer’s Duck” has been noticed for centuries, even being painted by J. J. Audubon himself. But, he called it the “Bemaculated Duck”, an apparent misspelling of the descriptor, bimaculated, meaning “marked with two spots.” The Brewer’s Duck is an intergeneric hybrid between a Mallard (Anas platyrhynchos) and a Gadwall (Mareca strepera).

This bird was originally spotted at Bush Conservation Area on February 23rd by Michelle Davis and reported via eBird and MOBIRDS. These photos were taken on February 24th.

The Brewer’s Duck is a true blending of its two-species heritage and they apparently are quite variable in appearance.

In the above photo, the blue speculum patch can be seen, coming from the Mallard. The fine lines of the Gadwall can be seen on the breast and sides. The head is a mixture of both species. Some green can be seen towards the back of the head, although this could only be seen at just the right angle to the sun. The bill is also a mix of the yellow Mallard’s and the all black Gadwall. In my opinion, the feet are more reminiscent of the color of the Gadwall’s feet.

A nice comparison of Mallard, Brewer’s and Gadwall drakes.

So far I have been unable to find out much about the Brewer’s Duck from books or internet sources and I have lots of questions. This bird seemed to mostly associate with Gadwalls. Is this common, or does it depend on which species was the mother? Does the parentage have to be directional? Are they fertile? How common are they?

Thanks for the visit!
-OZB