[va-bird] [Fwd: Re: [MDOSPREY] Goose Subspecies of Maryland]
- From: Susan Heath <sheath@xxxxxxx>
- To: VA Birds <va-bird@xxxxxxxxxxxxx>
- Date: Fri, 23 Jul 2004 11:14:08 -0400
VA Birders,
Jim Stasz posted an informative message about telling the now separate
Cackling Goose from the Canada Goose. It is forwarded here with
permission. There has been a lively exchange on MDOsprey about this
split if anyone wants to lurk and get more information. Although I'm
sure many of you have seen these birds in Virginia over the years (I saw
them annually while doing my waterfowl surveys in Fauquier County),
VARCOM has no documented sightings so we request that sightings of this
species be submitted at least until we build up a few records. If
anyone has pictures of past sightings, we would appreciate that those be
submitted for review so we have pictorial evidence to put in the
archives. Thanks.
Sue
-------- Original Message --------
Subject: Re: [MDOSPREY] Goose Subspecies of Maryland
Date: Fri, 23 Jul 2004 09:53:39 -0400
From: Jim Stasz <Jlstasz@xxxxxxx>
Reply-To: Maryland Birds & Birding <MDOSPREY@xxxxxxxxxxxxxxxxxxx>
To: MDOSPREY@xxxxxxxxxxxxxxxxxxx
In a message dated 7/22/2004 9:48:50 PM Eastern Daylight Time, David
Mozurkewich <mozurk@xxxxxxxxxxxxxxxx> writes:
Is there a good reference for identifying the subspecies of Canada Goose?
Does anyone know which subspecies of Canada Goose occur in Maryland and
what are the relative abundances?
Hi Folks!
Several Maryland briders have been looking at geese for a long time now. The
Yellow Book has some information in Appendix 1, but that is partially
out-of-date. I have seen Cackling Goose in every county except Garrett &
Allegany. The predominant type is "Richardson's" a.k.a. "hutchinsii" and is
usually associated with flocks of migrant Canada Geese. A very few birds found
with Snow Goose flocks may be a different subspecies, but I am unwilling to put
a name to those yet [they could be "minima"].
There is no one good reference. The systematics of the Canada Goose group has
been problematic since before 1950. Older literature used scientific names in
papers that were just plain wrong because of a mixup in the Type Specimens.
This in part explains why "Richardson's Goose" once called Branta canadensis
hutchinsii, and now know as Branta hutchinsii, is not called "Hutchins' Goose".
For a very long time the scientific name used was Branta canadensis
richardsoni, until someone discovered a mistake in the Type Specimens.
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].
Just about any flock of 500+ migrant Canadas will have one or two Richardson's.
Typically they are in pairs and any count over 10 is good. The maximum I have
ever seen in a single flock is 26.
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
Jim Stasz
North Beach MD
jlstasz
--
Susan A. Heath
George Mason University
Environmental Science Department
Fairfax, VA
Secretary, Virginia Avian Records Committee
Keeper, Virginia Comp List at www.virginiabirding.org
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