Belle Isle Ross's Goose X ?? - 07 Mar 2011

This morning Allen Chartier reported that he had seen and photographed both a dark morph Ross's Goose and a White-fronted Goose near the north fishing pier on Belle Isle Park in the Detroit River.  He would later clarify the ID of the Ross's Goose and suggest that it is a hybrid of questionable origin. 

Allen mentioned the following:

"I have posted several of my photos of the Ross's Goose found on Belle Isle, Wayne County, today (March 7) at the following site:
http://www.umich.edu/~bbowman/birds/se_mich/photos.html

The bird appears to show the proper shape, proportions, and size for a Ross's Goose, though it does not show the classic plumage for a blue morph. It may be an intermediate morph, as there should be more dark coloration on the breast and sides. It may also be a juvenile molting into adult plumage (it looks like there are pinfeathers on the lower neck), as the back coloration is rather dull and the tertials don't show the classic blue morph pattern either. An interesting little goose for sure. I've also posted one photo of the Greater White-fronted Goose that was accompanying it, at least when first found."

Some suggestions have been made that the bird might be Ross's Goose X Cackling Goose hybrid.  I lack any experience or proper reference material to comment on the bird, so I'm passing on any attempt at an ID.

I did find an interesting article online regarding identification of Blue-phase Ross's, Intermediate and Lesser Snow Geese for those of you inclined to read type-writer type fonts...  Surfbirds (Schmoker &Frieberg, 2010) has a nice article about Ross's and Snow Geese that show nice reference images.  Here's an article discussing different hybrid combinations of Ross's Geese from GoBirding.Eu. with reference images.

I will say that I drove over to Belle Isle early yesterday afternoon to look for the two birds w/ the hopes of getting some photos.  Blue-phase Ross's Goose are extremely rare, so I was excited to perhaps see one.

I'll also say that I had one of the most enjoyable digiscoping outings when I found the 'dark' Ross's Goose X ?? and spent better part of 30 minutes photographing it under perfect lighting conditions at a comfortable distance of ~ 90'.  I was also lucky to run into Jim Fowler, who suggested that I get some good pics of the bird's bill, which didn't have the coloration of a 'normal' Ross's Goose.  Having never seen a 'dark' Ross's Goose before I figured I better get as many diagnostic images as possible, in case it turned out to be a questionable ID.

Having posted a few images on my Digiscoping Blog yesterday afternoon, I came home last night to first of several comments suggesting that the bird was not a pure Ross's Goose.  I thought I'd list some of the comments (sources kept confidential).

The first comment I received suggested that I "@x*&%$;&@"; learn how to ID birds!"
I replied, "Ok, Mom! I will!"...

Other, more civilized notes were sent w/ these comments:

"If you get a good look at the base of the bill on this goose, you can see that there is NOT a vertical base but rather a curved edge against the feathers - conclusion, there is SNOW goose in this guy:("

"I think this is almost certainly a hybrid, and most likely a Ross's x white-cheeked goose based on upperparts coloration and bill pattern. The dark margins to the bill are not good for Ross's Goose of any age; overall the bill is similar in coloration to several presumed Snow x Canada/ Cackling Goose hybrids that I've seen in recent years in PA, NY, and Manitoba I think it would likely be wishful thinking to accurately pick Cackling or Canada for the other parent, but I suppose overall size and structure would favor Cackling.

On a related note, here's a photo of a bird that I think is a good example of a juvenile dark morph Ross's Goose that Melissa Roach and I saw at close range in New Mexico on 21 Feb 2011 in a megaflock of Snow and Ross's Geese at Bosque del Apache NWR:
http://www.flickr.com/photos/bonxie88/5508672252/

Though the tomium has a bit of a grin and the bill/ face junction is
slightly curved, I think this is actually quite typical of most/ all
juvenile Ross's Geese, something I think is often overlooked in
discussions of possible Ross's x Snow Goose hybrids. This is the only
dark morph bird of this age class that I've seen."

"Very interesting bird - I've been studying the various photos intently, and am not sure what to make of this bird in terms of age and ID. The biggest problems I can see with the ID as Ross's Goose is the obvious curvature to the bill base/facial junction and the lack of blue caruncles on the bill base, and possibly body size (a bit big?). Also, it doesn't seem to match any age of dark ROGO (with the caveats that the definition of dark ROGO may be clouded by its rarity and lack of knowledge of whether the dark morph allele might only come from Snow Goose introgression). If it was an adult, why is the nape and crown white and the breast mottled (both should be solidly dark). If a juvenile molting into formative plumage why is the face all-white (juvs have all dark heads and would be going from darker to paler in the face)? Molt would have had to start on the head and complete on the head before proceeding to the "intermediate" areas (breast, nape/crown). The beak pattern does look immature to me (irregular black patches, lacking caruncles and blue coloration on its base). Not sure what to make of it without some more research!"

I'll update this post if any new information comes in.  In the meantime, its a pretty bird that deserves some attention for its beauty!

More photos are here:

http://www.pbase.com/jourdaj/110307belleisle&page=all

All were digiscoped using a Zeiss 85T*Fl Spotting scope w/ 45X wide eyepiece, Nikon Coolpix P6000 and homemade adaptor.

Belle Isle Park, Detroit US-MI (42.3414,-82.9764), Wayne, Michigan, US
Mar 7, 2011 11:00 AM - 12:20 PM
Protocol: Traveling
0.5 mile(s)
Checklist Comments:     Cold, 1" snow on ground
1 species (+1 other taxa)

Ross's x Cackling Goose (hybrid) (Anser rossii x Branta hutchinsii)  1     Interesting goose among Canada Geese shows white head / small bill of Ross' Goose but dark body of Canada/Cackling Goose. Blog post and ID discussion at: https://birdingthroughglass.blogspot.com/2011/03/belle-isle-rosss-goose-x-07-mar-2011.html
Canada Goose (Branta canadensis)  85

View this checklist online at https://ebird.org/checklist/S164794231

This report was generated automatically by eBird v3 (https://ebird.org/home)