Mallard (I think)? American Black Duck? Hybrid? (1 Viewer)

[has530]

I was going through photos from a month or so back when I remembered taking a photo of a weird duck which I assumed was a mallard with it's head feathers coming in due to my location (Oakland, CA, USA) but I am now having a sliver of doubt on the ID based on a few things:

• The sharpness of the line separating green and and tan at the nape
• The single curl on the tail
• Someone posted a photo of a bird that looks an awful lot like this recently claiming it to be a hybrid.

Everything else points to mallard for me. Tell me this is just a mallard with its breeding plumage coming in.

 

[aeshna5]

I don't think it's a hybrid. Looks like a drake Mallard with a slightly abnormal head pattern to me.

 

[mummymonkey]

That head pattern is seen on a lot of hybrids too. Is that a neck ring?
The online images of mallard x Mexican duck are close.

 

[raymie]

Pure Mallard. A bit of an odd plumage, but no clear signs of introgression with any other species.

 

[Alexander Stöhr]

Hello,

it might well be an intersexual bird, an older female that develops partly male plumage due to hormonal changes. Normally the ones that I think I can name as such have more brownish patterned feathers on the flanks and breast, but yours is surely within variation for this.

Some excellent Information in german here:

„Intersexuelle“ Stockenten in der Südsteiermark / Intersex Mallards – notebook

www.khil.net

Stockenten-Hybrid

And here an intersexual hybrid from one of Jörns excellent papers: https://niedersachsen.nabu.de/imper...qual-hochw-druck_final-23092013_reduziert.pdf

 

[Ruff-Leg]

So, this is from maybe February? Mallards molt into breeding plumage in autumn, don't they? (And as I recall anatid breeding plumage is basic?)

I can't comment on any strange hormones, but it's definitely not a Black. I'm in SE AZ, and we see MALL x MEDU all the time, and I don't see any plumage evidence of introgression. Plus, mightn't Oakland be out of range?

Just a Mallard.

 

[Joern Lehmhus]

Please , do you have any pictures showing bill pattern and color? it could be a bird with an intersex plumage ( mostly old females ) , but it might also be a mallard with some American black duck genes - not a first generation cross, but these hybrids are fertile and can backcross to either parent.

 

[Joern Lehmhus]

some examples :

birds with Mallard and American black duck genes, that seem to be a bit more on the Mallard side:

https://www.birds.cornell.edu/crows/images/MallardBlackDuck589a.jpg

https://static.wixstatic.com/media/2e39dd_98aac5ea0591406dab2f206c9d4c7c6d~mv2.jpg/v1/fill/w_560,h_374,al_c,q_90,enc_auto/American%20Black%20Duck%20x%20Mallard%20hybrid-972.jpg

https://flic.kr/p/6bHHdw

https://flic.kr/p/96f7X

Intersex plumaged mallards:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNzAqE2DMPyZ08AcEhyphenhyphenkcW2hXKbSpC2nIt2v_nFFOxqeJCxUhYqBQdXS8lllDKwbty7czxufx9Bld69aI3j8T9a7ZJF4xhgARJ24Yv7VuvbwOSHFGRaP9Tu115EPZuCUBBycCQAPVZqaLH/s1600/1825.jpg

https://birdsandmusings.ca/wp-content/uploads/2021/11/homher-returns-03.jpg?w=1024

https://flic.kr/p/2kzd51E

So you see one important point is the bill pattern and color,

a pure yellow bill would indicate a male mallard with black duck hybrid ancestry,

an orange bill with black markings or an all black bill would indicate an intersex plumaged female mallard

 

[has530]

Please , do you have any pictures showing bill pattern and color? it could be a bird with an intersex plumage ( mostly old females ) , but it might also be a mallard with some American black duck genes - not a first generation cross, but these hybrids are fertile and can backcross to either parent.

I wish! It was tucked the entire time I was around.

Thanks for the replies everyone, I had not considered an intersex mallard even though I was vaguely aware of this phenomenon. Certainly interesting things to think about!