Monday 8 May 2017

White Ibis x Scarlet Ibis

White Ibis x Scarlet Ibis hybrid, Aruba Salina (Aruba, off Venezuela), 12th April 2017 - copyright Steve Mlodinow
(photo ID: 3202)


Steve tells us that this hybrid isn't at all rare in some colonies in northern Venezuela and Columbia leading some to speculate that Scarlet and White Ibises are colour morphs of the same species.  In an article in Colonial Waterbirds 10.1 111-114, Cristina Ramo and Benjamin Busto document 40 mixed pairs and 14 mixed copulations in the Venezuelan Llanos and proposed that they should be treated as different subspecies of one species.  But whether they are colour morphs, different subspecies or different species, most if not all of the main taxonomic authorities are still treating them as separate species at the moment.

It is reported that captive Scarlet Ibises receiving inadequate levels of β-keratin in their diet turn pink, and such birds may be difficult to distinguish from hybrids (see The Chat 53: 90-91 for example).  If anyone has any information on how they may be differentiated, please get in touch.

In Aruba neither species is common.  Steve tells us that Scarlet Ibis has been nearly annual during the last 5 years, with 2-3 birds involved. This is the first hybrid.  A White Ibis with an abnormally dark bill turned up the day after the hybrid - here they are together:

White Ibis x Scarlet Ibis hybrid (right, with White Ibis; same bird as in photo ID 3202 above), Aruba Salina (Aruba, off Venezuela), 14th April 2017 - copyright Steve Mlodinow
(photo ID: 3203)


White Ibis Eudocimus albus
Scarlet Ibis Eudocimus ruber

Bufflehead x Hooded Merganser

Bufflehead x Hooded Merganser hybrid (right, with Bufflehead), Firestone Gravel Pits, Weld County (Colorado, USA), 2nd May 2017 - copyright Steve Mlodinow
(photo ID: 3218)


Steve notes that that there is a bit of a crest, which changes in shape over time as the bird assumes different attitudes.  The white on the head is also oriented more towards rear than top.  The bill and tail are longer than those of a Bufflehead, with the entire bird being a bit larger as well.

Bufflehead x Hooded Merganser hybrid (same bird as in photo ID 3218 above), Firestone Gravel Pits, Weld County (Colorado, USA), 2nd May 2017 - copyright Steve Mlodinow
(photo ID: 3219)



Bufflehead Bucephala albeola
Hooded Merganser Lophodytes cucullatus

White-cheeked Pintail x Cape Teal

White-cheeked Pintail x Cape Teal hybrid (with White-cheeked Pintail), JCB Lakes, Rocester (Staffordshire, UK), 11th April 2017 - copyright Philip Ridsdale
(photo ID: 3201)


The White-cheeked Pintail influence in this bird is fairly obvious but for me the other parent wasn't so clear.  Thanks to Joern for pointing us to the correct ID.

White-cheeked Pintail x Cape Teal hybrid (same bird as in photo ID 3201 above), JCB Lakes, Rocester (Staffordshire, UK), 11th April 2017 - copyright Philip Ridsdale
(photo ID: 3200)



White-cheeked Pintail Anas bahamensis
Cape Teal Anas capensis

Sunday 26 March 2017

Recent updates

Black-headed Gull x Mediterranean Gull hybrid, Christopher Cadbury Reserve, Upton Warren (Worcestershire, UK), 12th March 2017 - copyright John Oates
(photo ID: 3173)


Here's another of our regular posts letting you know what pages have been updated in the project recently.  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 page added for:

New photos added to:

Text updated in:


Don't forget you can follow us on Twitter at @BirdHybrids

Enjoy browsing - and please do contribute where you can!

Tufted Duck x Lesser Scaup

Tufted Duck x Lesser Scaup hybrid, Ambleside Duckpond, West Vancouver (British Columbia, Canada), 19th March 2007 - copyright Paul Kusmin
(photo ID: 3144)


It seems pretty clear that this bird is a Tufted Duck x Scaup sp. hybrid but whether Greater or Lesser Scaup is involved is not so straightforward.  The coarseness of the vermiculations on the upperpart is different from at least some Tufted Duck x Greater Scaup hybrids and I think that is very likely to point to Lesser Scaup parentage.  In the two photos (above and below) the darkness of the upperparts looks different - that is often true in Tufted Duck x Scaup sp. hybrids, varying according to light and angle to the observer.

Tufted Duck x Lesser Scaup hybrid (same bird as in photo ID 3144 above), Ambleside Duckpond, West Vancouver (British Columbia, Canada), 16th March 2007 - copyright Paul Kusmin
(photo ID: 3145)


Tufted Duck x Lesser Scaup was the suggested ID for the following bird on the other side of the Atlantic (Tufted Ducks are vagrants among Lesser Scaup in North America while Lesser Scaups are vagrants among Tufted Ducks in Europe, so the hybrid is just as likely to occur on either continent).  The identification of this bird was discussed but I couldn't see that any clear conclusions were reached - as always, comments welcome.  There is also a video of this bird on YouTube.

possible Tufted Duck x Lesser Scaup hybrid, Møllekrogen (Denmark), 14th October 2016 - copyright Rasmus Strack
(photo ID: 3065)



Tufted Duck Aythya fuligula
Lesser Scaup Aythya affinis

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:


Don't forget you can follow us on Twitter at @BirdHybrids

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 Würdemann'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

Common Goldeneye x Hooded Merganser

Common Goldeneye x Hooded Merganser hybrid, Ottawa River (Ontario, Canada), 26th October - copyright Gordon Johnston
(photo ID: 2997)


Goldeneye sp. x Hooded Merganser hybrids are fairly frequently reported in the wild and broadly speaking this is a typical plumage for either.  The majority of reports probably relate to Common Goldeneye x Hooded Merganser.  The head colour seems to reflect that of the Goldeneye parent species at least in many instances, but you can't really make that out here.  However the extent of white in the scapulars helps clinch this one as involving Common Goldeneye rather than Barrow's Goldeneye.

We already have a page featuting a probable female Goldeneye sp. x Hooded Merganser which, in view of the extent of yellow on its bill is possibly more likely to involve Barrow's Goldeneye.


Common Goldeneye Bucephala clangula
Barrow's Goldeneye Bucephala islandica
Hooded Merganser Lophodytes cucullatus

Great Egret x Snowy Egret

Great Egret x Snowy Egret hybrid, Fort de Soto Park, Pinellas County (Florida, USA), 18th August 2016 - copyright Dave Norgate
(photo ID: 2987)


Dave says this bird seemed intermediate in size between Great Egret and Snowy Egret.  Structurally it seems to have an intermediate neck length and shape - you can see a hint of the kinked shape of Great Egret in some of the photos but it's not as clear as in a pure bird.  The bare parts also seem to be consistent with expectations for this hybrid.  Certainly the legs are wrong for Snowy Egret being entirely black right down to the bottom of the feet.  The gape line only extends back to below the cetnre of the eye, just like it does on Snowy Egret.  On Great Egret it would extend right back to beyond the back of the eye.  The only pure species I could possibly turn this into is Intermediate Egret, which in some respects it quite closely resembles.  However, although the Asian form of Intermediate Egret apparently does adopt a black bill in breeding condition (I don't believe the African form does) this bird is showing no sign of being in breeding condition.  I don't think the bill structure is quite right for Intermediate Egret either, and of course an Asian Intermediate Egret is rather unlikely in Florida - there are one or two ABA-area records but only from the Aleutian Islands in western Alaska so far as I know.




Great Egret x Snowy Egret hybrid (same bird as in photo ID 2987 above), Fort de Soto Park, Pinellas County (Florida, USA), 18th August 2016 - copyright Dave Norgate
(photo IDs: 2988-2991)



Great Egret Ardea alba
Snowy Egret Egretta thula

Tuesday 28 February 2017

Little Blue Heron x Tricolored Heron

Little Blue Heron x Tricolored Heron hybrid, Hammonasset State Park (Connecticut, USA), 23rd July 2013 - copyright Len Blumin
(photo ID: 2917)


Len makes a good case for the hybrid ID of this interesting bird.  Initially I was not entirely convinced but thought it was worth putting out there for others to comment on, and to see if other birds like this come out of the woodwork.  Turns out it was worth it as more information came to light.

As Len says, this bird's posture and structure resembles that of a Tricolored Heron, and of course much of the plumage does too.  Apparently some think the bill is intermediate in structure between Tricolored and Little Blue - a bit too subtle for my eye if so.  The obvious anomaly for pure Tricolored in terms of plumage is the grey belly and thighs (better seen on the photos below) - Tricolored should be pure white here.  Len has considered if this might be melanism but thinks this is unlikely on feathers that should be pure white.  I wasn't so sure about that - certainly there are records of normally white herons that have appeared grey, although at least some of these have been contaminated rather than being genuinely melanistic.  Nevertheless, in some cases they had a very even covering of grey and contamination was not obvious, so I was not completely convinced that we could rule that out in this case.

There are a couple of other features that Len points to that support Little Blue Heron involvement.  One of those is the iris colour which Len describes as pale yellow, or straw yellow.  It's normally brown, red or pink on adult Tricolored Heron.  I think a pale yellow iris is ok on immature Tricolored Heron (but Len's bird doesn't show any signs of juvenile plumage) - is it ok in an adult?  I don't get to see many Tricolored Herons, being in the UK, so trawled through some images online.  On some birds the majority of the iris seems to be yellowish but surrounded by pink or red on the outside of it, while on others even that wasn't very clear, such as this one.  So wasn't quite sure about this - did this really rule out pure Tricolored Heron?

Finally Len also draws attention to the manner in which it was feeding.  He writes, "The bird foraged rather deliberately looking for fish, as we often see with the Little Blue, whereas the usual Tricolored foraging is often more active, even frenetic, recalling the fishing technique of the Reddish Egret cousin."

So, I wondered, is there enough to call this a hybrid, or is it more likely a very odd but genetically pure Tricolored Heron?  Well, it turns out there were 2-3 birds seen in the area in the autumn of 2011 which superficially resembled first calendary-year Tricolored Herons but with anomalies including excessive white in the plumage.  They continued into the following year and some observers recognised that the white in the plumage might be a result of hybridisation with Little Blue Heron, noting an intermediate bill structure.  However it was hard to be sure that the white wasn't down to leucism until the birds were seen again later on in 2012 and in subsequent years.  Just as Little Blue Herons of this age would turn from white to grey, the amolous features of these birds (or at least one of them) had turned from including too much white to too much grey.  The evidence for them being hybrids with Little Blue Heron had suddenly became a lot stronger.  The records have now been accepted on eBird as this hybrid.  Thanks to Steve Mlodinow for drawing my attention to this, and you can read about it more on Nick Bonomo's website and see photos of one of the birds in their second calendar-year.

Little Blue Heron x Tricolored Heron hybrid (same bird as in photo ID 2917 above), Hammonasset State Park (Connecticut, USA), 23rd July 2013 - copyright Len Blumin
(photo ID: 2918)



Little Blue Heron x Tricolored Heron hybrid (same bird as in photo IDs 2917-2918 above), Hammonasset State Park (Connecticut, USA), 28th July 2013 - copyright Len Blumin
(photo IDs: 2919-2920)


Little Blue Heron x Tricolored Heron hybrid (same bird as in photo IDs 2917-2920 above), Hammonasset State Park (Connecticut, USA), 31st July 2013 - copyright Len Blumin
(photo ID: 2921)



Little Blue Heron Egretta caerulea
Tricolored Heron Egretta tricolor