Birds

Hybrid Mallards

February 28, 2011 by Corey 27 Comments

Mallards can be dirty ducks.  Very, very, dirty ducks.  And while ducks in general are known for their hybridizing ways, none are as prolific and undiscriminating as Anas platyrhynchos.  The list of species that Mallards are known to have hybridized with is long and in some cases Mallard genes threaten to flood the gene pool of other species.  Note that in discussing hybrids here I am not including the wide variety of “Manky Mallards” which result from domestication and from wild Mallards mating with a variety of domestic breeds.  What will be covered in this post is the offspring of Mallards and other species of wild ducks, some of which are startlingly beautiful.

First, however, we should take a look at the ordinary Mallard, both male and female, so as to establish a baseline, if you will, for Mallard-ness.  Below are ordinary and, so far as I can tell, pure, Mallards.

pair of ordinary Mallards, Saratoga Springs, NY

a small flock of ordinary Mallards in Central Park, New York City

The most likely of other species for Mallards to hybridize with, at least in North America, is the American Black Duck Anas rubripes.  Hybrid male Mallard X American Black Duck can be rather readily identified.  They tend to look like the American Black Duck but with Mallard-green on the head.  Often they have the Mallard‘s curled tail feathers and paler coloration then a pure American Black Duck on their back and flanks.  When one takes into consideration backcrosses there is a bit of variety but it should be apparent when one is dealing with a male American Black Duck with even a bit of Mallard in it.  Hybrid females are more difficult but can be picked out by looking through female Mallards and finding a darker individual and then looking for other characteristics that don’t match either Mallards or American Black Ducks exactly, like the speculum having some white but not as much as a Mallard would.  That’s how I found the female featured below.

pure American Black Duck Anas rubripes in Queens, New York

two male Mallard X American Black Duck in Nassau County, New York, though the one in the back might be a backcross

female Mallard X American Black Duck in Queens, NY

Another bird the Mallard hybridizes with relatively often is the Northern Pintail Anas acuta.  The resulting duck is beautiful and whenever a photographer sees one he takes advantage for sure.  I have not yet laid eyes on a Mallard X Northern Pintail but I can’t wait until I do.

Northern Pintail Anas acuta at Bolsa Chica Ecological Reserve, California

Northern Pintail X Mallard in British Columbia © Rick Wright (used with permission)

The Pacific Black Duck Anas superciliosa is a simply gorgeous duck, especially considering its limited palette,  that also occasionally gets involved with Mallards and the result is, sadly, somewhat less stunning.

Pacific Black Duck Anas superciliosa Victoria, Australia,by Fir0002/Flagstaffotos released under GFDL

Mallard X Pacific Black Duck in New Zealand by” ischa1″ who released the image into the public domain

When Mallards mix with Gadwall Anas strepera the resulting offspring is known as Brewer’s Duck, named by John James Audubon after his friend, the ornithologist Thomas Brewer.  Of course Audubon thought that the bird he shot in Louisiana was an entirely new species instead of the hybrid that it is.

male and female Gadwall Anas strepera in New York

Mallard X Gadwall or Brewer’s Duck, both above and below, in Maryland © Bill Hubick (used with permission)

Less famous but just as striking is the match-up of Mallard and Spot-billed Duck:

a Mallard X Spot-billed Duck hybrid © Dave Johnson (used with permission)

Teals are nearly as indiscriminately amorous as Mallards (see our in-depth analysis of Hybrid Teals), so evidence of teals hybridizing with Mallards makes perfect sense. Photographer C G Gustavsson captured shots of what appears to be a Eurasian Teal x Mallard in Copenhagen, Denmark, which he’s graciously shared with us here:

a Eurasian Teal X Mallard © C G Gustavsson (See all of C G Gustavsson’s amazing hybrid ducks and geese in his Flickr photostream)

Mallards are fascinating creatures in and of themselves and become even more so when their genes mix with other ducks.  I hope you enjoyed this small gallery and check back now and then as I plan to keep it growing because, of course, these few ducks are just a small sample of the hybrid Mallards out there in the world.

If you have a good image of a Mallard hybrid that I can add to this post please feel free to leave a link in the comments or email it to 10000birdsblogger AT gmail DOT com.  Thanks!

Written by Corey
Corey is a New Yorker who lived most of his life in upstate New York but has lived in Queens since 2008. He's only been birding since 2005 but has garnered a respectable life list by birding whenever he wasn't working as a union representative or spending time with his family. He lives in Forest Hills with Daisy and Desmond Shearwater. His bird photographs have appeared on the Today Show, in Birding, Living Bird Magazine, Bird Watcher's Digest, and many other fine publications. He is also the author of the American Birding Association Field Guide to the Birds of New York.