Friday, 28 February 2014

Snow Goose x Cackling Goose

probable Snow Goose x Cackling Goose hybrid, Longmont (Colorado, USA), 14th November 2013 - copyright Cathy Sheeter
(photo ID: 1853)


A naturally-occurring hybrid that can be extremely difficult to tell apart from Snow Goose x Canada Goose hybrids, or indeed Ross's Goose x Canada/Cackling Goose hybrids.  Cathy tells us that the first bird was smaller than the Snow Goose but slightly larger than the Cackling Geese (Richardson's hutchinsii) present on the pond.  It's bill was shorter than usual for this hybrid (more similar to Ross's hybrids) but it seemed to show a very small grin patch and the size indicated Snow Goose hybrid rather than Ross's Goose hybrid.




probable Snow Goose x Cackling Goose hybrid (same bird as in photo ID 1853 above), Longmont (Colorado, USA), 14th November 2013 - copyright Cathy Sheeter
(photo IDs: 1849-1852)


Here's another slightly different bird from Cathy:

Snow Goose x Cackling Goose hybrid, Green Valley Ranch Rec Center Ponds, Arapahoe County (Colorado, USA), 23rd January 2015 - copyright Cathy Sheeter
(photo ID: 1830)


Steve tells us this is the most common of the Snow/Ross's x Canada/Cackling combos in Colorado and identifies the next example as involving Cackling Goose rather than Canada Goose on account of it being less bulky than the accompanying Lesser Canada Geese (form parvipes).



Snow Goose x Cackling Goose hybrid, Frederick, Weld County (Colorado, USA), 29th January 2014 - copyright Steve Mlodinow
(photo IDs: 1502-1504)


The next one was also smaller and had a slimmer bill than a Snow Goose x Lesser Canada Goose hybrid at the same site.



Snow Goose x Cackling Goose hybrid, Greeley, Weld County (Colorado, USA), 26th November 2011 - copyright Steve Mlodinow
(photo IDs: 1345-1347)


The birds in the next two sets are both identified by a combination of size and the presence of a grin patch.  One is darker than the other suggesting blue and white morphs of Snow Goose.  One has a lot of pink on the bill but the other, unusually, has a lead-grey bill.



Snow Goose x Cackling Goose hybrid, Frederick, Weld County (Colorado, USA), 22nd December 2013 - copyright Steve Mlodinow
(photo IDs: 1122-1124)



Snow Goose x Cackling Goose hybrid, Longmont, Boulder County (Colorado, USA), 17th November 2013 - copyright Steve Mlodinow
(photo IDs: 1136-1137)


Steve informs us that the next bird was a bit bigger than the surrounding Cackling Geese.  The relatively long bill points away from Ross's Goose, and the grin patch (though reduced) is in keeping with other presumed Snow x Cackling Goose.

Snow Goose x Cackling Goose hybrid, Loveland, Larimer County (Colorado, USA), 27th November 2013 - copyright Steve Mlodinow
(photo ID: 1128)


The blue morph Snow Goose like plumage of some of these birds may be an additional pointer towards Snow Goose hybrid rather than Ross's Goose hybrid.  That's true of the next bird which also has a relatively long bill and largish head.

Snow Goose x Cackling Goose hybrid, Poudre River, Greeley, Weld County (Colorado, USA), 3rd February 2013 - copyright Steve Mlodinow
(photo ID: 1219)


The next one was a similar size to a Richardson's Cackling Goose with which it seemed to be paired, but the bill seems too long and the head to bulky for it to be Ross's x Cackling.



Snow Goose x Cackling Goose hybrid, Siena Pond, Broomfield County (Colorado, USA), 7th January 2012 - copyright Steve Mlodinow
(photo IDs: 1326-1328)


A second bird at the same place and date proved equally difficult - it had a delicate feel suggestive of Ross's Goose x Cackling Goose but the dark plumage and long bill are typical of Snow Goose x Cackling Goose hybrids.





Snow Goose x Cackling Goose hybrid, Siena Pond, Broomfield County (Colorado, USA), 7th January 2012 - copyright Steve Mlodinow
(photo IDs: 1329-1333)


Steve tells us that the Cackling Geese in this picture are mainly Richardson's hutchinsii, probably including the small runt just right of the hybrid.

Snow Goose x Cackling Goose hybrid, Windsor Lake, Weld County (Colorado, USA), 10th December 2014 - copyright Steve Mlodinow
(photo ID: 1712)


With the following two captive birds it wasn't easy to see whether the Branta parent was Canada Goose or Cackling Goose, however the zoo advised that they were the offspring of a pairing between a Snow Goose and a Cackling Goose.



captive Snow Goose x Cackling Goose hybrids, Halle (Saxony-Anhalt, Germany), 1st November 2014 - copyright Joern Lehmhus
(photo IDs: 1647-1649)





captive Snow Goose x Cackling Goose hybrids (same birds as in photo IDs 1647-1649 above), Halle (Saxony-Anhalt, Germany), 1st November 2014 - copyright Joern Lehmhus
(photo IDs: 1650-1653)


The next one would be easier if it had a bigger grinning patch.  Some of us think it's got enough of one not to rule out Snow Goose involvement, though others have come to a different conclusion.  For me the head shape - quite squared in some of the photos - is very suggestive of Cackling Goose (probably Richardson's hutchinsii) but the bird seems large and long-billed for a Ross's x Cackling hybrid, so my tentative ID would be Snow x Cackling.  Some commentators agree with me but some think Ross's x Cackling.  Any other input is welcome, as always.






possible Snow Goose x Cackling Goose hybrid (or Ross's Goose x Cackling Goose; with Cackling Geese), eastern New Mexico (USA), 30th January 2012 - copyright Deb Whitecotton
(photo IDs: 2143-2148)


Steve nailed the next on in flight!  He notes: "This goose looks vaguely like a Blue Goose, though head entirely white and rump/tail pattern more like Cackling/Canada.  The bird's size and shape in field yield the ID as Snow x Cackling.  Snow x Canada would have been larger, and larger billed."

Snow Goose x Cackling Goose hybrid, near Windsor, Weld County (Colorado, USA), 2nd December 2015 - copyright Steve Mlodinow
(photo ID: 2326)


When Steve found 3 young geese with 13 Snow Geese in the vicinity of a mixed flock of Cackling and Canada Geese, his first though was "intermediate" blue Snow Goose.  But they seemed smaller, and as he got closer it became clear that they were intermediate in size between that of Cackling Goose and Snow Goose.  Moreover their bills were rather slim with just a hint of a grin patch.  Steve also notes that the primaries were brown, whereas they are black in Snow Geese (both blue and white morphs).



Snow Goose x Cackling Goose hybrids (with Snow Goose and Cackling (and Canada?) Geese), Weld County (Colorado, USA), 25th January 2016 - copyright Steve Mlodinow
(photo IDs: 2710-2712)


Steve felt that Snow Goose parentage was clear on the next bird.  It was much larger than a Cackling Goose apparently, though Steve say the one closest to it was tiny.  The bill is stubby though, and Steve sayss that Canada (presumably Lesser Canada in Colorado) x Snow Geese tend to be larger bodied than this bird, with a longer bill.

Snow Goose x Cackling Goose hybrid (with Cackling Geese), Severance, Weld County (Colorado, USA), 26th February 2016 - copyright Steve Mlodinow
(photo ID: 2728)


Even Steve is stumped by the next one, so maybe he is human after all!  He says,
"I am just not certain of this bird. Instinct makes me go with Snow x Cackling, but the bird was larger than this photo might suggest (it is with moffitt-type Canadas) and has a longish bill for that cross... but I just can't convince myself that it is a Snow x Canada, which often just look bulkier."
Snow Goose x white-cheeked goose sp. (Cackling or Canada Goose) hybrid (with moffitti-type Canada Geese), Windsor Lake, Weld County (Colorado, USA), 26th February 2016 - copyright Steve Mlodinow
(photo ID: 2730)


The next bird was larger than the Cackling Geese in the flock it associated with.  Steve points out that a Snow Goose x Canada Goose should be larger and larger headed, typically with a more robust bill.  He also points out that it is a "blue morph" hybrid.  As well as the dark colouration, the streaking on the vent is typical of blue morph hybrids.

Snow Goose x Cackling Goose hybrid (with Cackling Geese), Stewarts' Pond, Weld County (Colorado, USA), 21st March 2016 - copyright Steve Mlodinow
(photo ID: 2769)


Snow Goose x Cackling Goose hybrid (with Cackling Geese), Sloan's Lake Park, Denver County (Colorado, USA), 13th December 2016 - copyright Steve Mlodinow
(photo ID: 2883)


Snow Goose x Cackling Goose hybrid (with Cackling Geese), Frederick Recreational Area, Weld County (Colorado, USA), 11th December 2016 - copyright Steve Mlodinow
(photo ID: 2884)


So far all the photos have been of wild birds in North America but this hybrid can occur in captivity in Europe too, as the following photos show.




captive Snow Goose x Cackling Goose hybrid, Halle Zoo (Germany), 21st September 2016 - copyright Joern Lehmhus
(photo IDs: 2896-2899)



(See also: Snow Goose x Canada Goose, Snow Goose x Barnacle Goose, Ross's Goose x Canada Goose, Ross's Goose x Cackling Goose)



Snow Goose Anser caerulescens or Chen caerulescens
Ross's Goose Anser rossii or Chen rossii
Cackling Goose Branta hutchinsii

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