iridescence?

[NancySullivan]

My pied mostly steel gray female, mated with an almost solid white drake, (he has a charming black crest and one black spot generally hidden under a wing), has hatched 7 ducklings.  The darkest is mostly a dark chocolate, although it appears to have a blackish iridescent sheen on the wings and tail.  (They are only 7 weeks old and I don't know how to sex them til they get older...).

Is this uncommon, or is there a mallard or something else lurking in its genetic history?

[randiliana]

Don't know how common that is, the blacks are always irridescent. But there is no mallard lurking. Muscovies aren't related to mallards and when you cross them with other breeds of ducks, you will get mules, ducks that cannot reproduce.

[Cathy]

Yes, chocolate is one of the colors that will have a green or purple iridescence.  I don't know what a black iridescence would be; unless it's just a very dark chocolate color that is really close to black.

[rollyard]

And it may not be chocolate?  I understand that you also have a brown coloured bird in the states that you call Sepia, is that correct? (see my post in Genetics).  If it is chocolate, then the choc coloured duckling could be either male or female, depending on which parent carries the choc gene.  I know this because the choc (ch) gene is a recessive sex linked gene so you need a double dose in the drakelets, but the young ducks being hemizygous can only inherit the one choc gene from the drake.

In other words, if the choc duckling turns out to be female then your white drake has hidden chocolate under the white.  Whether the blue duck carries the choc gene (if it is choc) is immaterial because she can't pass the sex-linked gene onto her daughters.  But if both your birds (white drake & blue duck) are carrying the choc gene then some of the drakelets bred could also end up chocolate (along with some young ducks).  The snag as I see it though is the dominant white (P).   

If he is pure for the autosomal white dominant gene then he would also have passed that on to all of the ducklings so they should all be predominantly white.  He must be heterozygous for the dom white gene & this young duck has missed out on the white gene by the looks.  From my reading white birds that are heterozygous for the gene P can present with variable speckling/spotting with no uniformity in pattern.

Or maybe something else layed in the nest?  Or maybe I have it wrong!

Cheers     

[Cathy]

Yes, I believe the heterozygous whites have the black caps that will molt out after the first molt.

I'm by no means an expert, but no one in the Muscovy world that I'm familiar with actually refers to a sepia although I do believe that it might be in Holderread's book as well as some Hollander papers, possibly.  I know that in Australia they refer to a chocolate-like bird as a bronze, perhaps that is the equivalent to sepia?  We don't have any birds like that here that I'm aware of.