Possible shelduck hybrid, tadorna x ferruginea, Central Spain (2 Viewers)

[fdokykcu]

This duck (middle one) was seen this afternoon at Alcazar de San Juan (Central Spain) in an marsh holding about 4,000 ducks of different species. On a quick search I've found some hybrids of the proposed parents showing white eye ring and patch in the bill base. Notice also the light breast band (in the field I could see it better than in this photo). Undertail coverts showed a similar color to those of common shelduck. It didn't fly so I couldn't see any wing pattern, but it behaved feeding and moving as all the other wildfowl around for about an hour. Common Shelduck is frequent here, right now over 500 in the lake. Wild Ruddy Shelduck is quite rare, although one of uncertain origin has been recently reported from here.

I'm sorry I don't have better photos but it was far away

I would like to hear your opinions about this ID

 

[stevethehydra]

Common x Ruddy Shelduck hybrids are variable, so it could be, but they tend to be darker, especially on the head: http://birdhybrids.blogspot.co.uk/2015/02/ruddy-shelduck-x-common-shelduck.html

Your bird looks rather closer in overall coloration to Ruddy Shelduck x Egyptian Goose*: http://birdhybrids.blogspot.co.uk/2014/03/egyptian-goose-x-ruddy-shelduck.html but also doesn't perfectly match (and I don't know if you have Egyptian Geese around?) - it also looks small for that combination, especially by comparison to the Mallard (assuming it's a wild-type drake rather than a domestic with wild coloration...) - so I don't know for sure! Dave Appleton and/or Joern Lehmus might want to have a look at this one... (I'm not sure how, but the last couple of times I've mentioned Dave's name in a hybrid duck thread, he's popped up...)

*note that despite the English popular name, this isn't that unlikely a hybrid as Alopochen is actually very closely related to (might even deserve to be 'lumped' into) Tadorna and not very closely related at all to true geese. They have also hybridised with Mallards: http://www.gobirding.eu/Photos/EgyptianGoosexMallard.php - ought to be considered a "duck" rather than a "goose" really!

 

[fdokykcu]

Thank you very much Steve, I'm still wondering if it could be tadorna x ferruginea or even tadorna x tadornoides... I've checked the Egyptian goose option but it seems to me less similar to what I saw

Perhaps I can get a better photograph next weekend, but it is not easy,
This marsh area doesn't have a resident of domestic ducks, so the mallard near him is a wild one.

Common x Ruddy Shelduck hybrids are variable, so it could be, but they tend to be darker, especially on the head: http://birdhybrids.blogspot.co.uk/2015/02/ruddy-shelduck-x-common-shelduck.html

Your bird looks rather closer in overall coloration to Ruddy Shelduck x Egyptian Goose*: http://birdhybrids.blogspot.co.uk/2014/03/egyptian-goose-x-ruddy-shelduck.html but also doesn't perfectly match (and I don't know if you have Egyptian Geese around?) - it also looks small for that combination, especially by comparison to the Mallard (assuming it's a wild-type drake rather than a domestic with wild coloration...) - so I don't know for sure! Dave Appleton and/or Joern Lehmus might want to have a look at this one... (I'm not sure how, but the last couple of times I've mentioned Dave's name in a hybrid duck thread, he's popped up...)

*note that despite the English popular name, this isn't that unlikely a hybrid as Alopochen is actually very closely related to (might even deserve to be 'lumped' into) Tadorna and not very closely related at all to true geese. They have also hybridised with Mallards: http://www.gobirding.eu/Photos/EgyptianGoosexMallard.php - ought to be considered a "duck" rather than a "goose" really!

 

[Joern Lehmhus]

It is Tadorna tadorna x Tadorna ferruginea, probably a female, compare with these:

https://www.flickr.com/groups/444365@N25/discuss/72157601886415063/

https://www.flickr.com/photos/14195020@N08/8739646854/in/album-72157602145597586/

https://www.zoochat.com/community/media/hybrid-tadorna-spp.210727/full?d=1357678684

http://www.123rf.com/photo_20922969...rruginea-ruddy-shelduck-kolomenskoe-memo.html

bird in second link was a female from behaviour ....I have once seen photos of two birds this hybrid combination, of which I was told that the sex had been determined.
The bird that was male had a dark head and a white neck ring as the Spanish bird, the female bird had no neck ring and white around the eye and base of the bill similar to the Bristol Zoo bird in link 1, and the birds in links 2 and 3.

Interestingly the book "Hybrid Ducks" from the Gillham brothers also mentions this hybrid combination and has photos of a male and a female. The male there also looks like the picture from Spain, the female is similar to that picture from Bristol Zoo.

So I think this could perhaps be a constant difference between the two sexes in this hybrid combination.

However there are sometimes birds with a lighter brown head, without white eyering and bill base as in probable female, but with a white neck ring as in probable male. I think these are possibly also male.

 

[fdokykcu]

Thank you so much for your answer! If I get better photos I'll post here

It is Tadorna tadorna x Tadorna ferruginea, probably a female, compare with these:

https://www.flickr.com/groups/444365@N25/discuss/72157601886415063/

https://www.flickr.com/photos/14195020@N08/8739646854/in/album-72157602145597586/

https://www.zoochat.com/community/media/hybrid-tadorna-spp.210727/full?d=1357678684

http://www.123rf.com/photo_20922969...rruginea-ruddy-shelduck-kolomenskoe-memo.html

bird in second link was a female from behaviour ....I have once seen photos of two birds this hybrid combination, of which I was told that the sex had been determined.
The bird that was male had a dark head and a white neck ring as the Spanish bird, the female bird had no neck ring and white around the eye and base of the bill similar to the Bristol Zoo bird in link 1, and the birds in links 2 and 3.

Interestingly the book "Hybrid Ducks" from the Gillham brothers also mentions this hybrid combination and has photos of a male and a female. The male there also looks like the picture from Spain, the female is similar to that picture from Bristol Zoo.

So I think this could perhaps be a constant difference between the two sexes in this hybrid combination.

However there are sometimes birds with a lighter brown head, without white eyering and bill base as in probable female, but with a white neck ring as in probable male. I think these are possibly also male.

 

[stevethehydra]

Interesting, it's obviously a very variable combination, but you could be right on there being a male/female difference... perhaps the Common Shelduck genes are more strongly expressed in males for some reason? The Common x Ruddy hybrid that I saw at Rutland Water a few years ago, which had a dark head and white neck ring almost like a male Mallard, was fairly definitely male in behaviour (chasing after and trying to mate with Egyptian Geese, most of which it was pretty much the same size as) - so this and that are at the extreme ends of a spectrum in both size and plumage... would kind of make sense if you took the sexual dimorphism of both Common and Ruddy and "added it together"?