Thursday, 2 March 2017

Recent updates

apparent Great Blue Heron x Great Egret hybrid, Fort de Soto Park, Pinellas County (Florida, USA), 17th August 2016 - copyright Dave Norgate
(photo ID: 2976)


At last I have managed to clear nearly all of the backlog of photos waiting to be uploaded here since my previous update, far too long ago.  Below is a summary of what's gone in.

As always, a big thanks to all who have contributed photos and/or insights, and if you haven't done yet or have more to offer then please get in touch.  You can comment on any thread if you have anything to say about the hybrids or topics covered, and if you have any photos you would be willing for us to use, please let us know (e.g. by emailing us).

The recent updates are summarised below but remember you can find an index list linking you to ALL the bird hybrids featured so far here:
And an index list of all the bird hybrid topics covered so far here:



So, the recent updates are:


New Bird Hybrid pages added for:

New photos added to:

Text updated in:


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Enjoy browsing - and please do contribute where you can!

Dunlin x White-rumped Sandpiper

Dunlin x White-rumped Sandpiper hybrid, Rock Point Provincial Park (Ontario, Canada), 19th May 2016 - copyright Chris Cheatle
(photo ID: 2931)


There have now been quite a range of hybrid shorebirds recorded but this is the first calidrid hybrid we have featured in the Bird Hybrids project.  Hopefully others will follow soon...

Apparently Chris's excellent set of photos were reviewed by two published shorebird authors, an OFO (Ontario Federation of Ornithologists) and EBird reviewer and confirmed as this combination by all. This spring bird appears to be in breeding plumage - juveniles moult out of juvenile plumage during their first winter and the patterning and freshness of the feathers in May mean these are not retained non-breeding feathers.  Once that is understood it becomes clear that no pure species fits the bill.  The head pattern and the breast spotting running down the foreflanks recalls White-rumped Sandpiper whereas the rufous in the scapulars is too extensive for that species.  The bill is intermediate between the two species and Chris reports that the rump was generally white.








Dunlin x White-rumped Sandpiper hybrid (same bird as in phtoo ID 2931 above), Rock Point Provincial Park (Ontario, Canada), 19th May 2016 - copyright Chris Cheatle
(photo IDs: 2932-2939)



Dunlin Calidris alpina
White-rumped Sandpiper Calidris fuscicollis

Wednesday, 1 March 2017

Black-bellied Whistling-Duck x Fulvous Whistling-Duck

Black-bellied Whistling-Duck x Fulvous Whistling-Duck hybrid, Moon Lake, Progreso Lakes, Hidalgo County (Texas, USA), 28th December 2016 - copyright Daniel Jones
(photo ID: 2998)


Hybrids between various species of Whistling-Duck seem to crop up quite frequently in captivity but wild-bred Whistling-Duck hybrids seem to be much more unusual.  This bird has the dark chestnut upperparts of Black-bellied with subtle pale tips to the feathers that are intermediate between the two species (plain on Black-bellied, clearly barred on Fulvous).  The dull head, the bill and legs lacking bright colours and the lack of a black belly are all possible on a young Black-bellied Whistling-Duck, but that cannot be the explanation here as the belly is also distinctly orange.  The vent (beneath the tail) is white, like Fulvous, and the black marks on the foreneck also recall those on a Fulvous Whistling-Duck.  Daniel's flight photos also reveal that this bird is missing the pale stripe through the centre of the upperwing that is found on Black-bellied Whistling-Duck





Black-bellied Whistling-Duck x Fulvous Whistling-Duck hybrid (same bird as in photo ID 2998 above; with Black-bellied Whistling-Ducks), Moon Lake, Progreso Lakes, Hidalgo County (Texas, USA), 28th December 2016 - copyright Daniel Jones
(photo IDs: 2999-3003)



Black-bellied Whistling-Duck Dendrocygna autumnalis
Fulvous Whistling-Duck Dendrocygna bicolor

Greater White-fronted Goose x Lesser White-fronted Goose

probable Greater White-fronted Goose x Lesser White-fronted Goose hybrid, Oudeland van Strijen (Zuid-Holland, Netherlands), 22nd February 2015 - copyright Diederik Kok
(photo ID: 3010)


There is quite a lot of variation in both Greater and Lesser White-fronted Geese so proving hybrids between them is quite difficult.  I am not entirely certain that pure Greater White-fronted Goose can be discounted for this individual as there probably isn't any single feature shown by this bird that does not sometimes appear on them.  However the combination of conspicuous yellow eye-ring, limited dark belly markings and slightly short-looking very pink bill make me think it is a good candidate.  There isn't much in the size or structure visible in the photos to clinch it though, so I am a bit cautious about labelling this as a definite hybrid.


probable Greater White-fronted Goose x Lesser White-fronted Goose hybrid (with Greater White-fronted Geese; same bird as in photo ID 3010 above), Oudeland van Strijen (Zuid-Holland, Netherlands), 22nd February 2015 - copyright Diederik Kok
(photo IDs: 3011-3012)



Greater White-fronted Goose Anser albifrons
Lesser White-fronted }Goose Anser erythropus

Tunrda Bean Goose x Barnacle Goose

Tunrda Bean Goose x Barnacle Goose hybrid (with Tundra Bean Geese), Oost (Texel, Netherlands), 30th December 2016 - copyright Diederik Kok
(photo ID: 3006)


The pale cheek with a reddish brown lower rear section reminds me of some Red-breasted Goose hybrids but I don't think that can be the case here.  I've never seen Tundra Bean x Red-breasted but based on how White-fronted Goose x Red-breasted Goose hybrids look I would expect a darker body and a more obviously smaller bird.  So I think Barnacle Goose seems the better solution for the white-cheeked parent.  It would be difficult to say for sure what the grey goose parent was but the fact that it is surrounded by Tundra Bean Goose makes that a pretty good bet - and the bright orange legs and pale belly are certainly consistent with that.



Tundra Bean Goose Anser serrirostris (formerly Anser fabalis rossicus)
Barnacle Goose Branta leucopsis

Tundra Bean Goose x Greater White-fronted Goose

probable Tundra Bean Goose x Greater White-fronted Goose hybrid (with Tundra Bean Geese), Oost (Texel, Netherlands), 29th December 2016 - copyright Diederik Kok
(photo ID: 3004)


Convincing examples of hybrids between some of the wild Anser species that occur in Europe are surprisingly hard to come by.  Perhaps that is because the hybrids are genuinely scarce, or perhaps it is hybrids are difficult to detect and even harder to prove, with variation in parent species considerable.  I suspect it's the latter but maybe in time this will become more clear.  This one looks like a promising candidate to me, although proving it is not an odd but genetically pure Tundra Bean Goose is not straightforward.

The white round the base of the bill is not enough on its own to reject pure Tundra Bean Goose - quite often they have a little white round the bill.  Usually this is broken on pure birds, not surrounding the whole of the upper mandible in a continuous line.  Not only is it continuous here but it's quite broad at the top too.  Perhaps that is possible in pure Tundra Bean - it wouldn't surprise me if so - but this bird also has a lot of dark shading behind the white, something that I don't recall seeing to this extent on a Tundra Bean Goose.  The extent of orange on the bill may not be too excessive for Tundra Bean Goose (though is not usual) but it also seems to have a pinky tone to it.  I think in combination these features point to a likely hybrid origin, although I am troubled by how perfect the rest of the bird looks for Tundra Bean Goose.  Maybe it is just a very unusual Tundra Bean Goose, but I am more convinced by this bird being a hybrid than others I've seen where the hybrid ID has been suggested.

In addition Diederik thought this bird called differently from the Tundra Bean Geese.  He has a recording of it at waarneming.nl.  I think it's quite a subtle difference, but that may be because I don't hear Tunrda Bean Geese calling often enough!

As always, comments are welcome!

probable Tundra Bean Goose x Greater White-fronted Goose hybrid (same bird as in photo ID 3004 above; with Tundra Bean Geese), Oost (Texel, Netherlands), 29th December 2016 - copyright Diederik Kok
(photo ID: 3005)



Tundra Bean Goose Anser serrirostris (formerly Anser fabalis rossicus)
Greater White-fronted Goose Anser albifrons

Great Blue Heron x Great Egret

Great Blue Heron x Great Egret hybrid, Fort de Soto Park, Pinellas County (Florida, USA), 17th August 2016 - copyright Dave Norgate
(photo ID: 2976)


The long kinked neck of this intriguing bird is very much like that of a Great Egret, but in other respects the structure of this bird seems to resemble Great Blue Heron as much.  The grey plumage and the bill do not belong on a Great Egret, whereas the yellow lores must come from an Egret species.  The latter, along with the neck structure, help rule out W├╝rdemann's Heron (the hybrid or intergrade between Great White Heron (the white form occidentalis of Great Blue Heron that occurs in southernmost Florida) and typical Great Blue Heron.

Thanks to Steve Mlodinow for pointing out that this bird has been accepted as this hybrid by eBird reviewers and photographed by other observers over six months.










Great Blue Heron x Great Egret hybrid (same bird as in photo ID 2976 above), Fort de Soto Park, Pinellas County (Florida, USA), 17th August 2016 - copyright Dave Norgate
(photo IDs: 2977-2986)



Great Blue Heron Ardea herodias
Great Egret Ardea alba