Hi, Martin and tweets.

I think the black-headed, gray-backed ducks that puzzled people in
some past post (I saw the photo, but I can't find the URL now) that
you refer to here were blue Swedish ducks, just one of the many
breeds of Mallards. The plumage is fine for that breed, although the
gray bills, as I recall, are atypical for Mallards. But if you can do
just about anything to their feathers through selective breeding, I
assume bare-part colors can also be changed through "directed
evolution."

Mallards do indeed hybridize with Muscovies, but I don't think these
hybrids are all that common. I've never seen one with certainty, and
I look at weird park-lake ducks all the time. I am fairly certain
that some of the ducks that people have passed off as Mallard x
Muscovy Duck on various websites aren't, but instead are just Mallard
breeds. Remember, these birds aren't hybrids (a cross between two
species), just domestic breeds in the same sense that boxers and
poodles are breeds, or Plymouth rocks and leghorns, or Arabs and
Clydesdales. Breeds of a species can mate with one another (well,
maybe not a chihuahua and great Dane) and produce viable offspring.
Hybrids between species are very often infertile and very often at an
ecological or behavioral disadvantage compared with the parent species.

The website that Martin listed is a great place to start if you're
interested in weird waterfowl and different ducks.

Dennis

On Dec 8, 2008, at 12:01 PM, tweeters-
request at mailman2.u.washington.edu wrote:

> Date: Sun, 7 Dec 2008 16:40:59 -0800
> From: "Martin Muller" <martinmuller at msn.com>
> Subject: Re: [Tweeters] mystery geese/ducks
> To: <tweeters at u.washington.edu>, "Jim Greaves" <lbviman at blackfoot.net>
> Message-ID: <BAY102-DS3A8ADA643AA9EED20D834C7FD0 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Marvin,
>
> Sorry for the delayed response, I'm on tweeters digest mode.
> I'm not arguing with other opinions you received, just giving my
> two cents worth.
> Since we don't know the parentage we will never know for
> sure.......but, looking at your photos, my fist impression was
> Muscovy (white domestic variety) x Mallard hybrid.
>
> The heavy (keeled) body and relatively long squared-off tail, with
> the overall larger size. The bill is more mallard-like.
> Non of these characteristics by themselves rule out other
> possibilities, mind you.
> But check out the images of a pair of Muscovy Ducks on
>
> http://www.birds.cornell.edu/crows/domducks.htm<http://
> www.birds.cornell.edu/crows/domducks.htm>
>
> Note the female in the foreground, and her plumage coloration. I'd
> consider it a possibility, despite the birds in your pictures
> having more dark on the dorsal side of the neck.
>
> In the past we had a male Muscovy Duck (dark "wild" coloration) who
> produced some interesting mixed offspring with Mallard females who
> found themselves "in the wrong place at the wrong time." Those
> offspring were similar in build to the birds you show, but mostly
> irrdecent dark green (from the "wild" Muscovy cloration).
>
> Always fun to speculate.
>
> Martin Muller, Seattle, WA

-----
Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115
206-528-1382
dennispaulson at comcast.net



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