MD Osprey:

This is long, but might be of interest to those who wish to pry more deeply
into this matter. I have included some relevant portions of the AOU
supplement text and provided the references cited. I have intentionally
left the previous two messages included in this thread for continuity,
making this a very long message. (I have also not used italics for
scientific names to avoid stylized text ).


Here's what the AOU 45th supplement says about this Canada Goose split:

"Several genetic studies of geese, including recent work with
mitochrondrial DNA (van Wagner and Baker, 1986), Shields and Wilson 1987,
Quinn et al. 1991, Paxinos et al. 2002, Scribner et al. 2003) have verified
pervious suggestions based on differences in voice, nesting habits,
habitat, and timing of migration, as well as in color and size (e.g.,
Brooks 1914, Aldrich 1946, Hellmayr and Conover 1948), that the forms
treated as the single species Branta canadensis by all previous AOU
Check-lists and most other works actually constitute at least two species,
and further that each of the two species may be more closely related to
another member of the genus than to each other. Thus, we divide B.
canadensis by recognizing a set of smaller-bodied forms as the species B.
hutchinsii, and rearrange our representatives of the genus in the sequence
bernicla, leucopsis, huchinisii, canadensis, sandvicensis. Additional
analysis may result in further splitting."


Under the new Cackling Goose account, the AOU states that this species is,
"Casual or accidental in Hawaii and east to the Florida panhandle, and the
Atlantic coast of the United States from Maine to South Carolina. The
distribution of this small-bodied form includes that of the subspecies B.
c. hutchinsii, asiatica, leucopareia, taverneri, and minima as recognized
by Delacour (1956)."

[Note: one person has mentioned to me that Cackling Geese are frequently
kept in captivity!]


Under the revised Canada Goose account, the AOU states that the breeding
range extends down to "... Pennsylvania, northern Virginia, and Maryland.
... Birds in eastern states south of Great Lakes and Massachusetts result
from relatively recent natural southward extension of breeding range and to
a great extent from introductions. Feral populations resulting from
introductions may occur almost anywhere in the United States. ... Winters
through most of the United States ..."


Literature Cited

American Ornithologist's Union [AOU]. 2004. Forty-fifth supplement to the
American Ornithologist's Union Check-list of North American Birds. The Auk
12(3):985-995.

Aldrich, J.W. 1946. Speciation in the white-cheeked geese. Wilson Bulletin
58:94-103.

Brooks, A. 1994. The races of Branta canadensis. Condor 16:123-124.

Delacour, J. 1956. Waterfowl of the World, vol. 1. County Life Limited, London.

Hellmayr, C.E. and B. Conover. 1948. Catalogue of birds of the Americas,
part 1, no. 2. Field Museum of Natural History Zoological Series 13.

Paxinos, E.E., H.F. James, S.L. Olson, M.D. Sorenson, J. Jackson, and R.C.
Fleischer. 2002. MtDNA from fossils reveals a raditation of Hawaiian geese
recently derived from the Canada Goose (Branta canadensis). Proceedings of
the National Academy of Sciences USA 99:1399-1404.

Quinn. T.W., G.F. Shields, and A.C. Wilson. 1991. Affinities of the
Hawaiian Goose based on two types of mitochrondrial DNA data. Auk 108:585-593.

Scribner , K.T., S.L. Talbot, J.M. Pearce, B.J. Pierson, K.S. Bollinger,
and D.V Derksen. 2003. Phylogeography of Canada Geese (Branta canadensis)
in western North America. Auk 120:889-907.

Shields, G.F., and A.C. Wilson. 1987. Subspecies of the Canada Goose
(Branta canadensis) have distinct mitochrondrial DNAs. Evolution 41:662-666.

van Wagner, C.E. and A.J. Baker. 1986. Genetic variation in populations of
Canada Goose (Branta canadensis). Canadian Journal of Zoology 64:940-947.


Hope this helps ...

Phil


At 11:44 07/25/2004 -0400, you wrote:
>Jim,
>
>I appreciate your comments on the Richardson's Goose. After your post I was
>prompted to read the Canada Goose chapter in Palmer ("Handbook of North
>American Birds, Vol. 2, Waterfowl (Part 1)". On page 192, under the
>subspecies heading "hutchinsii",  I read "They are very small in size and
>rather light-colored, with pale breast; the bill appears stubby (for
>example, when compared with the typical 'parvipes'); white cheek usually
>continuous across the chin; ...."
>
>Perhaps you can give us some further comment on the chin since you say "The
>white cheek patches are typically separate and do not join under the chin
>[i.e. the chin is black, not white]. " Does Palmer's word "usually" and
>your word "typically" put the two of you in agreement - to a large
>degree?  :).
>
>According to Palmer, Minima is smaller than hutchinsii and "White of cheeks
>continuous across chin, or interrupted there partially or completely by a
>black stripe; even the entire chin may be black with white of cheeks
>reduced in area and having black feathers intermingled."
>
>Clearly size doesn't count, at least when separating species, and a black
>chin may not help much either.
>
>Bill shape may be the most reliable thing for identification, but viewing
>angle will be a field problem. Coloration may be good but then there is
>parvipes, which can be quite pale on the breast. Palmer doesn't mention
>back color, though.
>
>One problem, as I see it, is that if we don't know where a particular bird
>has bred in the Arctic, we won't really be able to throw it into the right
>pigeon hole, so to speak. Do you know if the scientific studies, upon which
>the final A.O.U. decision to split was based, discuss plumage difference
>between "hutchinsii" and the small races of the Canada Goose?
>
>And what about hybrids?! I love the prospects. I predict that gull
>arguments are going to subside for a while, to be replaced by years of
>goose arguments. When the migrants arrive many many fields of dreams await
>the optimist.
>
>Charlie
>
>>Most of the standard reference books [Kortright, Bellrose, Bent,
>>"Waterfowl of the World"] discuss subspecies and one can not be certain if
>>the name used is correct. Sibley illustrates one of the small Canadas, but
>>gives it the wrong name.
>>
>>Richardson's Goose is easy to pick out of a flock at a distance, not
>>because of size, but because of coloration. The back is much grayer [not
>>brown] and the chest is much paler. The birds are about 2/3 the size of
>>migrant Canada geese and half the size if resident Canada geese [note:
>>migrant Canadas average smaller than resident Canadas].  The bill is
>>closer to an equilateral triangle in shape than an isoceles triangle. The
>>white cheek patches are typically seperate and do not join under the chin
>>[i.e. the chin is black, not white].  A white neck band may or may not be
>>present [this is not a useful character for identicication].
>>
>>If I were to revise the Yellow Book, I would list Richardson's as a
>>regular annual bird [solid black square] in Prince George's, Kent,
>>Caroline, Queen Anne, Talbot, Dorchester and Worcester. It is slightly
>>less common, but not rare, in Cecil, Harford, Baltimore, Howard,
>>Montgomery, and Anne Arundel. Some counties, like Calvert and Washington,
>>just do not get large flocks of migrant Canada geese in winter, so the
>>records are fewer but the species is not unexpected.  I bet there are
>>records for Garrett and Allegany.
>>
>>Good Birding!
>>
>>Jim
>
>==================================
>Phil Davis      Davidsonville, Maryland     USA
>                 mailto:[log in to unmask]
>==================================