The goose on page 1 appears to be a hybrid Chen x Branta, referring to the genus Chen (probably Snow or Ross's) and genus Branta (probably Cackling or Canada). I received 6 comments from ID Frontiers listserve that suggest Snow Goose as one parent and Cackling or Canada Goose as the other parent. One comment suggested that this bird could be a second (or greater) generation hybrid. I believe that the short bill rules out Snow x Canada, as both have significantly larger bills. The size and shape of the bill is a perfect match for Richardson's Cackling Goose, suggesting that Cackling Goose is one of the parents (i.e. Snow x Cackling or Ross's x Cackling). Can Ross's x Canada be ruled out?
The dark brown body coloration, a feature not normally present in any plumage of Chen or Branta goose, is confusing. Also, the dark feathers on the vent are not a feature of either Snow or Ross's Goose among Chen species, nor any Branta species. "Melanism" may be the explanation. Chen x Branta hybrids apparently show some melanism or at least express dark phase Chen features (see pages 2-4).
I have added photos of 16 other apparent Chen x Branta hybrid geese. Several recent Colorado birds are on page 2. Three probable Ross's x Cackling Goose hybrids photographed by Bill Schmoker on pp 3-4 (for more discussion of these 3 birds from Boulder, Colorado, visit Bill's blog site at http://brdpics.blogspot.com/2009/02/faces-in-crowd.html). Additional Chen x Branta hybrids including a family group with 4 hybrid progeny from Colorado, 3 birds from Washington state (northwest USA) and another from the Netherlands have been added to p. 4.
