ID duck (hybrid ?) 4 Jan 2018 Portugal (1 Viewer)

[HLousa]

Hi,
this duck was observed and photographed in Cávado Estuary, Portugal, on the 4th of January 2018.
My first impression in the field was a odd looking American Wigeon, Anas americana.
My second thought was that there are semi-captive wildfowl in the area, so this bird might probably be an hybrid.

https://www.flickr.com/photos/142921790@N02/26121973588

On another forum it was suggested that this bird might be and hybrid between Anas americana X Anas sibilatrix.

There is also a post on flickr, 2011, of a bird that was identified as an hybrid Anas flavirostris X Anas sibilatrix
https://www.flickr.com/photos/8793530@N03/5343996770/
https://www.flickr.com/photos/8793530@N03/4914165698/
As far has I know these photos date from August 2011.

The plumage is far from being similar of the bird I saw, but it could be on eclipse plumage (?).

I have more photos but all with bird in the same position.

Can any one help on the ID of this bird? And would you care to elaborate?

All the best
Hugo

 

[Joern Lehmhus]

This is probably also Anas flavirostris x Anas sibilatrix. However it may be a female hybrid.

thatit is A.americana x Asibilatrix is out of question. the bill pattern is that of a hybrid wigeon with another duck species. (americana and sibilatrix have similar wigeon bill pattern -so their hybrids alos show the blue, blacktipped wigeon bill pattern)

look at the suspected parent species, there are several intermediate traits :
Anas flavirostris
https://www.hbw.com/sites/default/f...blic/ibc/p/_SML9557r_resize.jpg?itok=DqXZZOAt
pale yellowish areas on bill,ground pattern of head is identical to your bird (except for dark patch around eye, which comses from chiloe wigeon A. sibilatrix);
Look at A. sibilatrix, female in rear:
http://www.tier-fotos.eu/1024/chile-pfeifenten-paerchen-anas-sibilatrix-am-1442010-6709.jpg
the slight reddish brown hue of your hybrid is from sibilatrix

Ther are a few more things if that isn´t sufficient

 

[HLousa]

@Joern Lehmhus

Thanks for the reply and details. I'd like to hear about the other things you mentioned.

 

[Joern Lehmhus]

Some more points:
Bill shape is also intermediate between the parents; and look at the breast pattern , also intermedate between the scaly chiloe wigeon pattern and the spotted yellow billed teal breast.
the edges of the scapulars are white in chiloe wigeon, but light reddish brown in yellowbilled teal, slightly more like the teal in the hybrid.
yellowbilled teal has a grey tail , chiloe wigeon a black tail. The hybrid has a greybrown intermediate coloration (if it were a hybrid of 2 wigeons, the tail should be black)