Ruddy Shelduck x Common Shelduck

Ruddy Shelduck x Common Shelduck hybrid, Rutland Water (Rutland, UK), May 2010 - copyright Steve Graby

(photo ID: 1947)

Some examples of this hybrid look much closer to Ruddy Shelduck in appearance, but birds like this one, superficially resembling Australasian Shelduck, are quite typical.

Ruddy Shelduck x Common Shelduck hybrid (same bird as in photo ID 1947 above; with Egyptian Goose), Rutland Water (Rutland, UK), May 2010 - copyright Steve Graby

(photo IDs: 1942-1946)

Here is another bird, rather similar to the last but with perhaps greyer flanks.

Ruddy Shelduck x Common Shelduck hybrid, Thorpe Park (Surrey, UK), 23rd January 2014 - copyright David Darrell-Lambert

(photo ID: 2688)

The next bird's identity is not certain.  I am struggling to come up with any alternative, though I have not seen an example looking quite like this before.  Joern also finds it odd and hasn't seen a Shelduck hybrid like it before, so we must retain some doubt over its identity.  Nevertheless my rationale for feeling that Ruddy x Common Shelduck is the best-fitting (if imperfect) solution is as follows...

The extensive orange colouration presumably points to Ruddy or South African (Cape) Shelduck and the fact that this extends on to the head (and the breast and vent are quite dark) seems to point to Ruddy rather than South African.  The legs have a strong pink element which probably counts out any dark-legged species for the second parent, but leaving Common Shelduck (among others).  Most examples of Ruddy Shelduck x Common Shelduck hybrids look quite different, often showing a white collar and often showing grey flanks, but both of those features can be absent on this hybrid.  Other ideas are welcome though - please comment if you have any thoughts.

Something I didn't notice when I first looked at these photos is that there is a tiny patch of pink on the culmen of the bill, and also a slight hint of a raised knob at the base of the bill.  Both of these features would be compatible with Common Shelduck involvement.

One possible explanation for its unusual appearance is that it could be a backcrossed bird (Ruddy Shelduck x Common Shelduck hybrid as one parent, Ruddy Shelduck the other).  But Ian Gereg has raised another possibility.  There is a new colour mutation of Ruddy Shelduck called 'red' known in captivity which apparently looks like this bird.  At the moment we are not clear how this mutation is produced, but we suspect that it does not come simply from mutation in Ruddy Shelduck and no input from Common Shelduck, but perhaps the Common Shelduck input was some generations back?  We hope to find out more - if you are any clearer on the origin of this "mutation" then please get in touch.

captive probable Ruddy Shelduck x Common Shelduck hybrid (perhaps backcrossed; with Ruddy Shelduck), private collection (Staffordshire, UK), 29th March 2016 - copyright Brian Harris

(photo IDs: 2794-2798)

The next one is probably the same bird.

captive probable Ruddy Shelduck x Common Shelduck hybrid (perhaps backcrossed; with Ruddy Shelduck), JCB Lakes, Rocester (Staffordshire, UK), 30th March 2016 - copyright Philip Ridsdale

(photo ID: 3091)

Ruddy Shelduck Tadorna ferruginea 
Australian Shelduck Tadorna tadornoides
Common Shelduck Tadorna tadorna

Recent updates

You can always find the latest updates to this project by checking the Latest updates page at any time - this is updated at the end of any day when new pages are added or new photos or other information is added to existing pages.

We realise that some followers may prefer to subscribe by email (there's a button to subscribe on the right hand panel if you're using a PC/desktop not a mobile device).  If so you'll get notifications when new pages are added but I don't think you'll see updates to existing pages.  From time to time (maybe around weekly... we'll see how it goes) we will add a new "Recent updates" post highlighting anything that's been added recently - since the last Recent updates post.  That way everyone can see what's new.

To kick off, here's what's new over the last couple of weeks:



New bird hybrid pages added for:

• Ruddy Shelduck x South African Shelduck
• Eurasian Wigeon x American Wigeon
• Canvasback x Redhead
• Ring-necked Duck x Ruddy Duck
• Goldeneye sp. x Hooded Merganser
• Common Tern x Forster's Tern
• Clay-colored Sparrow x Field Sparrow

New photos added to:

• Greater White-fronted Goose x Canada Goose
• domestic Greylag Goose x Canada Goose
• Barn Swallow x Cliff Swallow

Big thanks as usual to all the contributors - and if you're reading this and have anything to contribute please get in touch!

Eurasian Wigeon x American Wigeon

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 15th January 2015 - copyright Keith Carlson

(photo ID: 2028)

Vagrant American Wigeons turn up regularly among the Wigeon flocks in western Europe and hybrids between the two species appear from time to time.  A similar situation occurs in east Asia, while the mirror situation occurs with Eurasian Wigeon turning up among American flocks in east and west North America (especially in the Pacific north-west, I understand).

The first series of photos here show what is assumed to be the same bird returning each winter for at least 9 consecutive years.

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 21st December 2007 - copyright Keith Carlson

(photo ID: 2018)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 11th January 2008 - copyright Keith Carlson

(photo ID: 2019)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 14th January 2009 - copyright Keith Carlson

(photo ID: 2020)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 5th December 2009 - copyright Keith Carlson

(photo IDs: 2021-2022)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 7th January 2010 - copyright Keith Carlson

(photo ID: 2023)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 6th December 2010 - copyright Keith Carlson

(photo ID: 2024)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 29h November 2012 - copyright Keith Carlson

(photo ID: 2025)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 18th December 2012 - copyright Keith Carlson

(photo ID: 2026)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 10th January 2014 - copyright Keith Carlson

(photo ID: 2027)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 15th January 2015 - copyright Keith Carlson

(photo ID: 2029)

Eurasian Wigeon x American Wigeon hybrid, Swallows Park, Clarkston, Asotin County (Washington, USA), 23rd November 2015 - copyright Keith Carlson

(photo ID: 2308)

Steve thinks the dark neck collar and chin may be atypical for this hybrid although it seems to be shown on both of the next birds.  There is quite a bit of variation in Eurasian Wigeon with respect to this feature so perhaps we should expect to see that variation come through in their hybrids?

Eurasian Wigeon x American Wigeon hybrid, Olympia (Washington, USA), 23rd January 2011 - copyright Steve Mlodinow

(photo IDs: 2186-2187)

Eurasian Wigeon x American Wigeon hybrid, Oak Harbor (Washington, USA), 19th December 2009 - copyright Steve Mlodinow

(photo IDs: 2219-2220)

Although this hybrid can occur on the eastern seaboard of North America, in Europe and in eastern Asia, here is another one from the west side of North America where it seems to be most frequently recorded.

Eurasian Wigeon x American Wigeon hybrid (with American Wigeons), Kelowna (British Columbia, Canada), 2nd February 2015 - copyright Ian Walker

(photo ID: 2786)

The next bird was reported as either an American Wigeon or a hybrid but by the time I arrived some people thought it might even be just a weird Eurasian Wigeon.  I can't see that personally, but it does look good for a hybrid.  My only hesitation is over whether Eurasian Wigeon x Chiloe Wigeon can be ruled out.  I would expect a Chiloe hybrid to show more orange tones on the flanks where as this bird showed very American-like deep brownish pink tones - however this may be within range for Eurasian x Chiloe (see the photos we have of that hybrid here, one of which looks rather similar to this bird).  Indeed Joern has also picked up on the possibility of this bird being Eurasian x Chiloe, though he is also uncertain.  He points out the extent of dark on the crown which is not typical of Eurasian x American, though sometimes this hybrid may have some dark in the crown.  Some Eurasian Wigeon can have some dark in the crown too, so this is perhaps not necessarily proof of Chiloe Wigeon influence, but maybe it does point that way.  The fact that my photos aren't good doesn't help!  Worth noting that Wigeon hybrids appear to be fertile so Chiloe Wigeon hybrid backcrossed with Eurasian Wigeon should also be considered.

possible Eurasian Wigeon x American Wigeon hybrid (with Eurasian Wigeon), Cley (Norfolk, UK), 7th February 2015 - copyright Dave Appleton

(photo IDs: 1814-1817)

The next bird seems like a fairly clear-cut hybrid.  Len points out that the pale forehead mark is two-toned.  The base of the bill is faintly outlined in black.  This bird was associating with American Wigeons.

Eurasian Wigeon x American Wigeon hybrid, Gallinas (California, USA), 18th January 2015 - copyright Len Blumin

(photo IDs: 2922-2924)

Eurasian Wigeon Anas penelope
American Wigeon Anas americana
Chiloe Wigeon Anas sibilatrix

Canvasback x (Redhead or Ring-necked Duck)

Canvasback x Ring-necked Duck or Canvasback x Redhead hybrid, Erie Reservoir, Boulder County (Colorado, USA), 4th February 2015 - copyright Steve Mlodinow

(photo ID: 1821)

Steve's photos of this one might not be his best but they were taken shortly before dusk on a cloudy day, so I think we can forgive him ;-)  He notes:

"The bill seemed to have some black around the base of the bill, and probably on the saddle [see photo ID 1819 below] as well as at the tip.  The bird looked paler than any of these photos indicated, with a distinctly darker head and upper neck.  No eyering."

Steve also tells us that there are photos of a male Canvasback x Redhead hybrid in the eBird collection that shows a bird "that alternates from the more Canvasback profile to that weird slope coming up of the bill and then flattening out on the crown".  He goes on to say:

"This bird has a bit more white around the face than I'd expect form this cross [Canvasback x Redhead].  It was with a Redhead and a Ring-necked Duck male, switching its attention from one to the other.  Its speculum was that of Ring-necked Duck/Canvasback/Redhead but not a scaup (or Tufted!).  My experience with Ring-necked Duck x Scaup hybrids is that the hybrids show the scaup parent's speculum.  The bird was smaller than the Redhead, so I wonder... Question, could this be a Canvasback x Ring-necked Duck?  I am actually leaning that way"

Canvasback x Ring-necked Duck or Canvasback x Redhead hybrid (same bird as in photo ID 1821 above), Erie Reservoir, Boulder County (Colorado, USA), 4th February 2015 - copyright Steve Mlodinow

(photo IDs: 1818-1820)

Canvasback Aythya valisineria
Redhead Aythya americana
Ring-necked Duck Aythya collaris

Goldeneye sp. x Hooded Merganser

possible Goldeneye sp. x Hooded Merganser hybrid, location unspecified but presumed to be shot in North America, date unspecified but presumed to be on or shortly before 4th February 2015 - copyright Billy Hull

(photo ID: 1824)

This is the second of the shot ducks I've been sent photos of in the last few days.  The correspondent (Bunn Boddie) wondered about Wood Duck x Goldeneye, but while I can certainly see Goldeneye in it I suspect the thinness of the bill may point to Hooded Merganser as the second parent.  This is a more likely hybrid - one that's known to occur regularly in the wild - and the wing pattern is more as I would expect on such a hybrid.

The yellow on the bill is more extensive than on Hooded Merganser or on typical Common Goldeneye, and that makes me wonder if the Goldeneye parent might have been Barrow's Goldeneye.  However, as some Common Goldeneyes can show more extensive yellow-orange colour on the bill than normal individuals I suspect they may carry the necessary genes to throw up such a feature in a hybrid.

To my eyes the photos seem to show a hint of green plumage on the head, especially at the rear of the crown.  I'm not sure if this is real, but if so that would suggest it is not a female Goldeneye x Hooded Merganser hybrid, but it may be ok for a first-winter male (or alternatively it could be an intersex female).

possible Goldeneye sp. x Hooded Merganser hybrid (same bird as in photo ID 1824 above), location unspecified but presumed to be shot in North America, date unspecified but presumed to be on or shortly before 4th February 2015 - copyright Billy Hull

(photo IDs: 1822-1823)

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

Ring-necked Duck x Ruddy Duck

 

unidentified duck, perhaps Ring-necked Duck x Ruddy Duck hybrid, shot in South Carolina (USA), 'recently' (as at 1st February 2015) - copyright Austin Braddell

(photo ID: 1799)

Unusually I've been sent two sets of photos of hybrid ducks that have been shot in America.  The first one came from Don Terrell and Austin Braddock.  It possessed a stiff tail making Don wonder if Ruddy Duck was involved.  He'd wondered about Ring-necked Duck x Ruddy Duck but felt the narrow black bill was unexpected.  My initial thoughts were that it might instead be a hybrid between a dabbling duck species (Anas sp.) and a diving duck (probably Aythya) but the more I look at it the more I am leaning towards Ruddy Duck being involved after all.  Maybe Don was right with Ring-necked x Ruddy?  

It should be noted that cross-genera hybrids involving Stifftails are very unusual.  Only one, a Greater Scaup x Ruddy Duck hybrid, is listed Eugene M McCarthy's Handbook of Avian Hybrids of the World (listed as questionable but to be firmed up in the second edition - big thanks to Eugene McCarthy for getting in touch about that).  I've not seen any reference to any others (although I did once get an all-too-brief view of a bird I suspected may have been a Tufted Duck x Ruddy Duck hybrid).   The photo above does seem to show a very Ruddy-like stripe across the face, although this isn't obvious in the photos below.  The plumage with its mottled appearance below and dark back and upper wings are perhaps consistent with a Ruddy Duck hybrid - and of course the tail seems that way.  The pale around the eye and behind the bill, plus the pale band on the bill, are consistent with a Ring-necked Duck hybrid, and the bill shape is certainly more Aythya than Ruddy Duck.

Austin is hoping to get the bird mounted so may have an opportunity to get some spread-wing photos.  Perhaps that will help us resolve this conundrum.

 unidentified duck, perhaps Ring-necked Duck x Ruddy Duck hybrid (same bird as in photo ID 1799 above), shot in South Carolina (USA), 'recently' (as at 1st February 2015) - copyright Austin Braddell

(photo IDs: 1795-1798)

Ring-necked Duck Aythya collaris
Ruddy Duck Oxyura jamaicensis

Clay-colored Sparrow x Field Sparrow

Clay-colored Sparrow x Field Sparrow hybrid, Grand Isle, Lake Champlin (Vermont, USA), May and July 1998 - copyright Dave Hoag

(photo ID: 1801)

Vermont is outside of the normal range for Clay-colored Sparrow but Dave sound-recorded a singing bird on Grand Isle between 29th May and 5th June 1997.  On 23rd July he recorded a second bird, but while this one shared the buzzy quality of Clay-colored Sparrow its song pattern, with added trill at the end, more closely resembled Field Sparrow.  Its plumage was intermediate too, ruling out any possibility that it was a Field Sparrow that had learned Clay-colored song.  Moreover Dave tells us that by August its face pattern remained different from Clay-colored Sparrow (not sharply defined as on worn adult Clay-colored), eliminating any chance that it was a Clay-colored Sparrow that had learned Field Sparrow song (also its bill was pink).

This bird returned in the summers of 1998 and 1999 when it was paired with a female Field Sparrow, and they raised 2-3 young successfully in 1999.

The Vermont Birds Records Committee concurred with Dave's identification and in 1999 the occurrence was published in Wilson Bulletin 111 (4): 581-584 along with sonograms of the bird's song.


Clay-colored Sparrow Spizella pallida
Field Sparrow Spizella pusilla

Common Tern x Forster's Tern

possible Common Tern x Forster's Tern hybrid (with Common Terns), Grand Isle, Lake Champlain (Vermont, USA), 22nd May 2013 - copyright Dave Hoag

(photo ID: 1800)

This bird was among 100 Common Terns but Dave tells us that this one was obviously much thicker-billed, paler-billed (and longer-billed?) yet lacked the longer and more orange legs of a Forster's Tern.  It's legs were red like those of Common Tern and Dave thinks its bill was maybe not orange enough for a typical Forster's Tern.

In additon Dave notes that the tail length relative to wing length was wrong for Forster's and the primaries were too dark.  The belly does seem white in all the photos.  No flight photos were obtained.

Dave tells us that Forster's Terns recently began nesting within a Common Tern colony on Lake Champlain - circumstances that make occurrence of hybrisation more likely than normal.


Common Tern Sterna hirundo
Forster's Tern Sterna forsteri