Tuesday, November 02, 2010

Weird Ducks (Mostly Mallards)

Late fall brings the welcome return of some large groups of birds like raptors, sparrows, and waterfowl. Large and colorful birds like waterfowl are usually easy to identify. From time to time, though, a duck or goose shows up that does not look exactly like the birds in the field guides. Take the duck on the right in the image above. I recognized this one right away, partly from experience and partly because it is one of the few waterfowl hybrids pictured in the large Sibley guide. This is a hybrid of a Mallard and an American Black Duck, possibly the same one that has been present in my local park for the past few winters. This bird has a green crescent on its head and the tail and back of a male Mallard, but otherwise the dark, cold tones of its plumage resembles an American Black Duck. The female Mallard alongside the hybrid seems to be its mate, as the two kept close to each other while moving around in the river.

Another weird duck is this white duck. The structure and what exists of a plumage pattern reveals that it has Mallard ancestry. I am not sure, though, how it got in its current form. It could be a leucistic wild Mallard, that is, a bird lacking sufficient pigment to color most of its feathers. The other possibility is that it is a domestic Mallard breed, or perhaps the result of a domestic Mallard breeding with a wild one. I lean somewhat towards the latter since there are so many exotic ducks in our local avifauna, but I could see a case for leucism as well. There are two more photos of the bird below.

Whatever the explanation for its appearance, it is a good reminder that common birds can be interesting, too!