Recent updates

Reeves's Pheasant x Ring-necked Pheasant (var. tenebrosus) hybrid, Threxton Hill (Norfolk, UK), 21st March 2015 - copyright Dave Appleton

(photo ID: 2154)

A few more updates during the past couple of weeks.  Thanks to all who have contributed photos and/or insights and if you haven't done yet 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).


Recent updates are below but remember you can find an index list linking you to all the bird hybrids featured so far here:

• Index of bird hybrids

And an index list of all the bird hybrid topics covered so far here:

• Index of bird hybrid topics

So, the recent updates are:


New bird hybrid pages added for:

• Lesser White-fronted Goose x Canada Goose
• Lesser White-fronted Goose x Cackling Goose
• Northern Pintail x Red-crested Pochard
• Bufflehead x Common Goldeneye
• Barrow's Goldeneye x Hooded Merganser
• Little Egret x Western Reef-Heron
• Pied Stilt x Black Stilt
• American Oystercatcher x Blackish Oystercatcher
• Galah x Little Corella
• Philadelphia Vireo x Red-eyed Vireo
• Blue-winged Warbler x Golden-winged Warbler

New photos added to:

• Greylag Goose x Canada Goose
• domestic Greylag Goose x Canada Goose
• Snow Goose x Canada Goose
• Snow Goose x Cackling Goose
• Ross's Goose x Cackling Goose
• Mute Swan x Whooper Swan
• Muscovy Duck x Mallard
• Wood Duck x Mallard
• Common Pochard x Ferruginous Duck
• Reeves's Pheasant x Ring-necked Pheasant
• American Herring Gull x Glaucous Gull
• Saker Falcon x Gyrfalcon
• White-crowned Sparrow x Golden-crowned Sparrow

Text amended in:

• Common Pochard x Tufted Duck

Information about other Aythya x Oxyura hybrids updated and corrected on following bird hybrid page:

• Ring-necked Duck x Ruddy Duck

Text amended in Bird Hybrid Topic page for:

• Hybrid speciation

Information and photo added to bird hybrid topic page:

• Conservation issues arising from hybridisation

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


Enjoy browsing - and please do contribute where you can! 

Northern Pintail x Red-crested Pochard

Northern Pintail x Red-crested Pochard hybrid, Valley Road Washlands, Nottingham (Nottinghamshire, UK), 11th March 2015 - copyright Chris Jackson

(photo ID: 2156)

It's reassuring when faced with a tricky hybrid duck when two people reach the same conclusion independently.  I saw these photos when Nick Crouch (@notbirdingnick) posted them on Twitter.  Pintail x Red-crested Pochard wasn't my first thought at all, but it's always worth flicking through the pages of the Gillham books when faced with an unfamiliar hybrid duck, and when I did so I came across a very similar bird, a Pintail x Red-crested Pochard.  I hadn't noticed the orange on the crown in Chris's photos but looking back at them I realised it did show.  I hadn't realised Nick had blogged about it too, and tentatively reached exactly the same conclusion.

And now Joern has added his weight to the ID too, based on his greater experience:

"A typical example of this cross in my opinion.  I have seen photos of at least 8 male birds of this cross (from France, from Switzerland, from Moscow, from UK), half of them with known captive origin.  Note that the brown of the head is variable, in most birds I have seen closer to Northern Pintail, but some appear more reddish, closer to Red-crested Pochard.  One bird had a marked pale area in the middle of the breast reaching upwads to the front of the neck but the sides of the breast were dark - this appeared as if the white breast of pintail came through.  All birds had a bill pattern closer to Northern pintail but the black was some more extended and below the blue-grey some red was coming through in the bill base or in the bill tip or both."

Northern Pintail x Red-crested Pochard hybrid (same bird as in photo ID 2156 above), Valley Road Washlands, Nottingham (Nottinghamshire, UK), 11th March 2015 - copyright Chris Jackson

(photo ID: 2157)

Northern Pintail Anas acuta
Red-crested Pochard Netta rufina

Little Egret x Western Reef-Heron

Little Egret x Western Reef-Heron hybrid, Santa Luzia (Algarve, Portugal), October 2006 - copyright Henrique Oliveira Pires

(photo ID: 2129)

In recent years a small number of Western Reef-Herons have been identified amongst colonies of Little Egrets in southern Europe. These have bred with the Little Egrets and some hybrids have been observed. Henrique Oliveira Pires has been fortunate to capture one such hybrid in southern Portugal on a couple of occasions.

It differs from pure Western Reef-Heron in a number of ways, including the all-dark legs and finer bill, but the identification of these two species is not always easy even without hybrids.  Henrique had photographed a similar bird at the same place five years previously - shown below.  Perhaps this was the same bird as a similar individual was photographed in the area by Ray Tipper in the years in between.  His photos taken in January 2001 and November 2002 were published in Birding World 14.2: 55 and Birding World 15.11: 462. 

Little Egret x Western Reef-Heron hybrid, Santa Luzia (Algarve, Portugal), October 2001 - copyright Henrique Oliveira Pires

(photo ID: 2130)

Little Egret Egretta garzetta
Western Reef-Heron Egretta gularis

Bufflehead x Common Goldeneye

Bufflehead x Common Goldeneye hybrid, Esquimalt Lagoon, Victoria, Vancouver Island (British Columbia, Canada), 2nd December 2009 - copyright Jim Craig

(photo ID: 2128)

What a smart bird!  And now who says hybrids are ugly?!  This one so superbly captured by Jim was among Bufflehead and Goldeneye wintering on the lagoon.

I have labelled all the birds on this page simply as Bufflehead x Common Goldeneye without any qualifier, which could be open to challenge.  I believe at least two of them were among Bufflehead and Common Goldeneye but the possibility that the Goldeneye parent was Barrow's is perhaps difficult to exclude with certainty.  Probably we need more experience of Bufflehead x Barrow's Goldeneye hybrids to be clear about the criteria for eliminating those.  I suspect that historically part of the rationale for identifying some such hybrids as involving Common Goldeneye rather than Barrow's was the head colour, Common Goldeneye having a green head sheen while Barrow's is more purple.  But we now know that head sheen colour in ducks is not necessarily helpful, for example Tufted Duck x Ring-necked Duck hybrids tend to show green head sheen despite both parent species normally looking purple.  Perhaps Barrow's hybrids might show other indications of different parentage in scapular pattern, head/bill shape, etc., but to me at least this is not yet clear.

Bufflehead x Common Goldeneye hybrid, Kelowna (British Columbia, Canada), 5th April 2016 - copyright Ian Walker

(photo IDs: 2780-2785)

Both presumed parent species were present with the next one below.  Matt tells us that it was slightly larger than the Bufflheads which is what it was mostly associating with.

Bufflehead x Common Goldeneye hybrid, El Campo, Tiburon (California, USA), 7th January 2014 - copyright Matt Brady

(photo IDs: 2121-2112)

Bufflehead Bucephala albeola
Common Goldeneye Bucephala clangula

Blue-winged Warbler x Golden-winged Warbler

Blue-winged Warbler x Golden-winged Warbler hybrid, Peveto Woods, Cameron Parish (Louisiana, USA), 15th April 2014 - copyright Matt Brady

(photo ID: 2115)

Two different forms of hybrid between Blue-winged and Golden-winged Warblers were separately named as distinct species, Brewster's Warbler and Lawrence's Warbler in 1874.  By 1881 Brewster had recognised that they were in fact hybrids, though it was many years before this was to become widely accepted.  A very interesting account by Leo Shapiro of the history - including much more recent studies - of these hybrids was published in Birding magazine (May/June 2005), accessible online here.

Blue-winged Warbler x Golden-winged Warbler hybrid (same bird as in photo ID 2115 above), Peveto Woods, Cameron Parish (Louisiana, USA), 15th April 2014 - copyright Matt Brady

(photo IDs: 2116-2119)

The next one is very similar to pure Blue-winged Warbler so obviously not a first-generation hybrid.  I had to look twice to see why it wasn't a Blue-winged Warbler - I guess it's the extent of white in the wing and the dark at the back of the ear-coverts?

Blue-winged Warbler x Golden-winged Warbler hybrid, San Francisco (California, USA), 17th September 2008 - copyright Matt Brady

(photo ID: 2120)

On this one, superficially closer to Blue-winged Warbler, the yellow wing-bars and the thickness of the dark stripe behind the eye are indicative of a hybrid - the type known as Lawrence's Warbler.

Blue-winged Warbler x Golden-winged Warbler hybrid, Rockfish Valley (Virginia, USA), 13th September 2012 - copyright Marshall Faintich

(photo IDs: 3158-3161)

And in contrast here is one more like a Golden-winged Warbler.

Blue-winged Warbler x Golden-winged Warbler hybrid, Blue Grass Valley (Virginia, USA), 19th May 2012 - copyright Marshall Faintich

(photo IDs: 3162-3167)

Blue-winged Warbler Vermivora cyanoptera
Golden-winged Warbler Vermivora chrysoptera

Philadelphia Vireo x Red-eyed Vireo

apparent Philadelphia Vireo x Red-eyed Vireo hybrid, Southeast Farallon Island (California, USA), 7th September 2008 - copyright Matt Brady

(photo ID: 2121)

This unusual hybrid was present from 7th to 13th September 2008 and was written up in Western Birds 41:4 (Terrill, Tietz and Brady, 2010).  I've not seen the full article but an abstract is available online.  This points out how seldom Vireo hybrids are reported, this one in particular being reported just twice before.  It was intermediate between the two presumed parent species in breast colour, head pattern, head shape and measurements.  The wing structure apparently eliminated Warbling Vireo and the South American form of Red-eyed Vireo as possible parent species.  This bird was also written up on the Los Fallarones website, and this provides a little more detail and a couple more photos.


Philadelphia Vireo Vireo philadelphicus
Red-eyed Vireo Vireo olivaceus

Barrow's Goldeneye x Hooded Merganser

Barrow's Goldeneye x Hooded Merganser hybrid, Lake Merritt, Oakland (California, USA), 19th December 2007- copyright Doug Greenberg

(photo ID: 2080)

Goldeneye x Hooded Merganser hybrids are not infrequently reported in North America but in most cases the Goldeneye parent is a Common Goldeneye.   This Goldeneye parent of this bird is believed to be a Barrow's.  Joern has mentioned that in his experience Common Goldeneye x Hooded Merganser hybrids generally show a greenish head gloss, more white on scapulars and paler flanks.  Some individuals also have odd white markings on the head (differing from those of either parent) - but of course it may be that this is true of some Barrow's hybrids too.

This striking bird wintered at the same site for several winters and has proved quite popular: many birders have travelled to see and photograph it - Doug's photos are especially impressive!

Barrow's Goldeneye x Hooded Merganser hybrid (same bird as in photo ID 2080 above), Lake Merritt, Oakland (California, USA), 19th December 2007- copyright Doug Greenberg

(photo ID: 2079)

 Barrow's Goldeneye x Hooded Merganser hybrid (same bird as in photo IDs 2079-2080 above), Lake Merritt, Oakland (California, USA), 16th December 2007- copyright Doug Greenberg

(photo IDs: 2077-2078)

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

Pied Stilt x Black Stilt

Pied Stilt x Black Stilt hybrid, Ashley River Mouth (Canterbury, New Zealand), on or before 13th January 2008 - copyright Ian McHenry

(photo ID: 2086)

New Zealand's Black Stilt, or Kaki, has the dubious honour of being one of the world's most threatened shorebirds - critically endangered with a population that has dipped to as low as 23 individuals.  Predation from introduced mammals and habitat loss (including as a result of hyrdo-electric schemes) are among its threats but a further threat is hybridisation with the more common Pied Stilt.  Pied Stilt, or White-headed Stilt, is the Australasian counterpart of the Black-winged Stilt that's widespread across Eurasia and Africa and the Black-necked Stilt of the Americas.

Hybrids typically show a black band across the breast, as shown in all of the photos presented here.

Pied Stilt x Black Stilt hybrid, Ashley River Mouth (Canterbury, New Zealand), on or before 24th November 2006 - copyright Ian McHenry

(photo ID: 2081)

Pied Stilt x Black Stilt hybrid, Christchurch (Canterbury, New Zealand), on or before 28th December 2007 - copyright Ian McHenry

(photo IDs: 2082-2084)

Pied Stilt x Black Stilt hybrid (with Pied Stilt), Ashley River Mouth (Canterbury, New Zealand), on or before 12th January 2008 - copyright Ian McHenry

(photo ID: 2085)

Pied Stilt x Black Stilt hybrid, Ashley River Mouth (Canterbury, New Zealand), on or before 16th December 2011 - copyright Ian McHenry

(photo IDs: 2087-2088)

Pied Stilt x Black Stilt hybrid (with Pied Stilt), Ashley River Mouth (Canterbury, New Zealand), on or before 17th December 2011 - copyright Ian McHenry

(photo IDs: 2089-2090)

Pied Stilt x Black Stilt hybrid, Miranda (New Zealand), 11th February 2017 - copyright John Oates

(photo ID: 3129)

Pied Stilt x Black Stilt hybrid, Ashley River Mouth (New Zealand), 18th February 2017 - copyright John Oates

(photo ID: 3172)

Pied Stilt Himantopus leucocephalus
Black Stilt Himantopus novaezelandiae

American Oystercatcher x Blackish Oystercatcher

American Oystercatcher x Blackish Oystercatcher hybrid, Puerto Pirámides (Chubut, Argentina), 26th October 2006 - copyright Vince Smith

(photo ID: 2091)

I am not sure how frequent this hybrid is, but it would be a hard job to separate it from an American Oystercatcher x Black Oystercatcher hybrid.  Fortunately the ranges of Black and Blackish Oystercatchers are fairly well separated so hopefully we won't have to answer that one!

American Oystercatcher x Blackish Oystercatcher hybrid (same bird as in photo ID 2091 above), Puerto Pirámides (Chubut, Argentina), 26th October 2006 - copyright Vince Smith

(photo IDs: 2092-2094)

American Oystercatcher Haematopus palliatus
Blackish Oystercatcher Haematopus leucopodus