Possible American Wigeon x Wigeon Hybrid (1 Viewer)

[Lancey]

Dear all,
While searching through my videos from last year I found film of a drake Wigeon I saw at Oare Marshes in Kent in March 2003 on several occasions.

The face showed a broad bottle-green stripe running down the cheeks and terminating down the side of the neck. This was most evident when the sunlight struck the bird. The crown wasn't the orange colour of a Eurasian Wigeon but more the cream of American Wigeon.

The body didn't look any different to me from that of a Eurasian Wigeon. I did discover a website which included a birder's diary about his birding trips in Japan. A photo of a hybrid Wigeon on the site, identified as a Eurasian x American, seems to match that at Oare to an uncanny degree. The photo I mean appears below along with two photos of the Oare bird.

However, is it as simple as this? I know Wigeon can be highly variable in the Far East (according to a recent British Birds article which included an illustration of a bird not too different to the Oare individual).

Is it a hybrid or an extreme variant? Any ideas?

Thanks,
Lancey

 

[Michael Frankis]

Hi Lancey,

I'd go with a hybrid. Much more likely in Britain that a Wigeon from the far east of Asia (and since American Wigeons also get into east Asia, who's to know those aren't hybrids, too?)

Michael

 

[Bluetail]

Hi Lancey. I think this is just a variant Eurasian Wigeon. I once saw a bird like this at Dawlish Warren, though the green on the head wasn't as marked as in your bird and disappeared altogether from some angles. I think we've had a discussion here before about this type of variant.

PS: Here it is: http://www.birdforum.net/showthread.php?t=12057

 

[Lancey]

Clarification

Thanks for your help so far. Just to make it clear - the photo on the far right of the trio is from the Japanese website and was identified as a hybrid by that observer - if that helps, though I rather doubt it somehow.

Lancey

 

[Edward woodwood]

I'd go with variant as well Jason, although hybrid is still possible

Latest ID paper in BB stated 'birds showing typical features of Eurasian in all other respects aside from head pattern are more likely to be variant than a hybrid.' More likely being the caveat i guess.

 

[Michael Frankis]

But why more likely?

Given the number of American Wigeon turning up over here, and in the Far East, there has to be a steady trickle of Am W genes into the regional populations. I'd reckon that most, very probably all, of these 'variants' showing some Am W characteristics are due to past hybridisation with Am W (anything from one to a hundred or more generations ago), than to de novo mutation entirely within the Eur W genome and devoid of Am W genes. The latter case strikes me as highly improbable.

Michael

 

[Edward woodwood]

dunno Michael.... just reporting what was in the paper, not really my opinion. I'm the Monkey Boy rather than the organ grinder here! I guess some of these variants must occur in populations of known provenace such as captive birds maybe? If not then the assumption of variant is a tad strange.....

maybe the start of a note to BB there Michael.....
howabout it?

 

[Stephen Dunstan]

But why more likely?

Given the number of American Wigeon turning up over here, and in the Far East, there has to be a steady trickle of Am W genes into the regional populations. I'd reckon that most, very probably all, of these 'variants' showing some Am W characteristics are due to past hybridisation with Am W (anything from one to a hundred or more generations ago), than to de novo mutation entirely within the Eur W genome and devoid of Am W genes. The latter case strikes me as highly improbable.

Michael

Michael,

I would be inclined to agree, but why then does it always manifest itself this way rather than in any other American Wigeon feature.

Regards,

Stephen.

 

[Michael Frankis]

Hi Stephen,

Presumably due to certain genes being dominant, as in the case I gave in the earlier thread (link in post #3 above) of the Pintail gene for a blue bill persisting several generations after the F1 hybrid in Mallards, when all other Pintail genes have been diluted to the point of invisibility

Michael

 

[Bluetail]

Hi Michael. But couldn't it be just as easily due to the two species' related ancestory rather than hybridisation? (I admit I don't know how close their DNA is, though.)

 

[Edward woodwood]

I will reread the paper when i get in tonight. The 'variant' tag must surely come from study of captive bred birds with known provenance as i mentioned above. There must be some science/facts behind this somewhere i presume or is it just one of those things that gets repeated to the point of being 'known to be true' by all? In some species 'odd' birds are always suggested to be hybrids.....with Am Wigeons they often seem to be thought of as 'variants' for some reason.....

 

[Michael Frankis]

Hi Jason,

If that was the case, then you'd expect the character to be shown by all (or at least many) individuals, not just an odd one occasionally, and particularly not just at the western and eastern extremes of the species' range

Michael

 

[Edward woodwood]

is this not similar to the dark headed Ruddy 'variant' perhaps discussed yesterday?

and in real life are genes that 'dominant' in a black and white sense? - isn't there something called pleiotropy where the result of combinations of different alleles can be extremely varied with some resultant phenotypes being very rare but still occuring..?

the above could be rubbish - it's a fair time since i studied this stuff!

 

[mountain man]

I'm inclined to agree with Jason. At the Hayle Estuary this winter I noted that perhaps 50% of Eur.Wigeon showed green head markings to varying degrees. For a hybrid I think there has to be a number of other features that suggest American.

 

[mountain man]

Is the bird on the far right the Japan one? The bill looks a bit more American than yours, but still not convinced...

 

[Michael Frankis]

Hi Tom,

Most, if not all, Euro Wigeon have a green spot immediately round the eye, which only shows well in good light from the right angle; but I think any wigeon showing a large green crescent like Lancey's photo, has at least some American Wigeon blood in it

Michael

 

[Bluetail]

Lancey's pics suggest the green on the head was only visible from some angles. For example, in the second pic the area immediately behind the eye looks chestnut and the green is only obvious towards the nape. In that respect it is similar to the Dawlish bird I saw (which, incidentally, only showed the feature on one side of the head - and I took trouble to confirm that difference was real and not due to angle of view). Also the Oare bird's green patch is less extensive than it would be on American Wigeon - it should not have a chestnut upper border. The Japanese bird has it right. And a further point: the green on American Wigeon is not a solid green; it is flecked, as is the rest of the head. In the few adult male Americans that I have seen, it was not nearly so striking as depicted in the average field guide. In the birds Lancey posted the green looks rather too pure to me.

This doesn't prove the Oare bird isn't a hybrid, but I'm not yet convinced.

 

[Lancey]

Further Clarification

Dear all,
An enlightening debate indeed which justifies the noteworthiness of such birds, in my eyes at least. Maybe part of the reason we lack facts about birds such as this, or the dark headed Ruddy Duck, is because they are all too easily glossed over and ignored as being too 'difficult'? Just a thought? Maybe that's why the existence of Caspian Gulls has only recently been noted - but I digress.

In answer to a few points raised above, yes, the Japanese bird is in the right-hand photo. Yes, the green on the face was more visible in bright sunlight (as originally mentioned). Mind you, do we know how visible the head pattern was on the Japenese bird in dull conditions?

Lancey

 

[Edward woodwood]

I think the facts are probably there just that we as humble birders probably don't have access to them. This kind of stuff isn't published in popular birding circles.

The dark-headed Ruddy is not a hybrid and may or may not be an escape... if not then it would appear to be a 'variant' so if this is the case then 'variants' certainly do occur. This could therefore be the case with Am. Wigeons.

I'd be grateful if anyone could comment on pleiotropic effects of genes and whether a rare change in one of several alleles controlling aspects of head pattern plumage could bring about variation like this in a small number of cases - also accounting for the lack of other expected 'hybrid' features in birds like this?

 

[HH75]

Hi all,
Just caught up with this thread today.In my opinion,this bird is most likely(those words again!) a variant male Eurasian Wigeon,simply because there are no other features that suggest genetic input from American.I'm not even convinced that the Japanese bird is a hybrid,but agree that it does look slightly more unusual.
Harry