The adult in all four shots is indeed an adult dark-morph Ross's Goose. Two dark-morph Ross's Geese, an adult and an immature, were with the white geese at the south end of the Salton Sea through the winter of 2004-2005 (North American Birds 59:323) with a photograph of the adult published (North American Birds 59:324). As you correctly noted, these birds are the same size and shape as the white Ross's Geese. They are noticeably blacker than the dark-morph Snow Geese, with the white on the head and neck restricted to the face. Because these birds are blacker than the dark-morph Snow Geese, the white on the tertials is more obvious than that on the dark-morph Snow Geese. All (about half-a-dozen) of the dark-morph Ross's Geese that I have seen have had white under-parts, which I believe is normal.
I believe the goose immediately ahead of the adult dark-morph Ross's Goose in the first shot is the immature present - the face on this bird was not the clean white as on the adult.
954 Grove Avenue
Imperial Beach, CA 91932
----- Original Message -----
Sent: Tuesday, December 18, 2007 7:56 AM
Subject: [CALBIRDS] Dark-morph Ross's Goose
As California seems to get most of the dark-morph Ross's Geese, I was
hoping that some of you that are might see a few of these birds would
look at some photos of a bird I found in TN. My only experience with
this bird was one at the Salton Sea a couple of years ago.
I posted 5 shots on my Pbase site, starting here:
The shots are a little distant.
This bird was part of flock of about 3000 Snow Geese, about a 50/50
split white to dark. Good numbers of Ross's were in the group as
well. We are seeing more and more Ross's all the time here in the
Mississippi River Valley, and though people are looking for them, to
knowledge this is the 1st promising bird from TN.
The bird struck me initially by how black it was, along with the neat
white face encased in black. Structurally, I couldn't tell any
difference in this bird and classic Ross's when side-by-side in
either size or bill characters. This bird had a straight border to
the bill, lacked any grin patch, and had the bluish base to the bill.
The head was nicely rounded. The coverts and tertials contrasted
strikingly white against the blackish body, but don't always show
that bright in some of the photos for some reason.
So far the opinion is it looks pretty good for a dark Ross's, but I
was wondering if it would be considered such on their home grounds.
Photos are very scarce, though it looks to be a dead-ringer match to
the one posted in the Calbirds photo under Waterfowl back in 2003.
Thanks for any and all comments.
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