Ross's Goose (possible hybrid with Snow Goose) (Chen rossii X C. caerulescens), Sweetwater Wetlands, Pima County

This Ross's Goose (which is possibly a hybrid) was discovered by Gavin Bieber at Sweetwater Wetlands in Tucson on 11 February 2009 and it was photographed by Andrew Core on 13 February 2009.

Ross's Goose does hybridize with Snow Goose.  Although many characters of this bird are consistent with Ross's Goose, some characters (particularly the long bill and the "grin patch" on the bill) that are more consistent with it being a hybrid.

Andrew Core provides this analysis:

"After looking at as many sources as I could, I am not sure I can say what this is. My best guess is 3/4 Ross's, 1/4 Snow (i.e., one Snow grandparent). In favor of Ross's: The bill border is slightly rounded but still pretty straight, there isn't much extension of the bill process, base of bill is bluish, the bird was fairly small, and head rounded, with eye close to bill.  In favor of Snow: not much... other than it's a white goose. In favor of hybrid: limited grin patch (though... I'm not sure how much Ross's can show. Sources seem to disagree on this point), bill border isn't perfectly straight, and most troubling, the bill is larger than typical for Ross's and is slightly convex

Here's some websites that had info:

www.birds.cornell.edu/crows/rossgoos.htm

home.montereybay.com/creagrus/hybgoose.html (look at last picture... bird on left looks a lot like SWW bird, and called a ROGO)

 www.birddigiscoping.com/2005/11/probable-rosss-goose-x-lesser-snow.html (again, similar, but called a hybrid here)

www.oceanwanderers.com/BlueGoose.html (see Fig 5, called "unknown")"

13 February 2009, photo by Andrew Core

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