MD Osprey:

A number of reports are being posted of Cackling Geese in Maryland 
and DC. When the AOU split Cackling Goose from Canada Goose over six 
years ago, they split AND then lumped and named the then current 
Canada Goose subspecies in an interesting (non-straightforward?) way. 
So, Cackling Goose now consists of four subspecies, each of which 
could possibly be split again in the future (per the AOU). Therefore, 
field birders are encouraged to try to determine, if possible, which 
species of Cackling Goose is present.

The expected subspecies in our region is the nominate "Cackling 
Goose" more commonly called "Richardson's" Cackling Goose (Branta 
hutchinsii hutchinsii) and is NOT reviewable by the MD/DC Records 
Committee; however, any other subspecies of Cackling Goose would be 
notable and unusual for our region and "reviewable" by the committee.

The common names of the other three subspecies are a real confusing 
mess and it is best to refer to them as shown below. All three winter 
in the western US. They are, from largest to smallest:

         Aleutian Cackling Goose (B.h. leucopareia) - Aleutian 
Cackling Goose is a good common name

         "Cackling" Cackling Goose (B.h. minima) - This was formerly 
called the Cackling Goose when it was a subspecies of Canada Goose. 
Some now call this the Lesser Cackling Goose; however, it's probably 
best to jusr refer to this taxon by its scientific species name "minima'

         Lesser/Taverner's Cackling Goose (B.h. taverneri) - This 
used to be one of the two taxa in the original Canada Goose complex 
(along with parvipes). Now, it is probably best to refer to this as 
Taverner's Cackling Goose


Notes:

1. There is a published reference in a European journal to a Lesser 
(taverneri?) that was banded in Maryland (!) and recovered in Europe. 
The records committee is trying to track down further information.

2. We also have a Maryland photo of a potential Lesser (taverneri?) 
that we will review in the future.


Birders are encouraged to try and separate Cackling Goose subspecies, 
if possible. Note: separation of the largest taverneri subspecies of 
Cackling Goose and the parvipes subspecies of Canada Goose is a 
difficult (at best), if not unresolved, field challenge. Sibley has 
addressed this challenge on his blog here ...

         http://sibleyguides.blogspot.com/2008/11/lesser-canada-goose-in-northeastern-us.html


FYI. Here are some good Cackling Goose identification reference links 
... I know, more than you (n)ever wanted to know ...

         http://www.irbc.ie/notes/cackling/cackling.php

         http://www.sibleyguides.com/2007/07/identification-of-cackling-and-canada-goose/

         http://stokesbirdingblog.blogspot.com/2009/11/cackling-geese-subspecies-in-east.html

         http://www.idahobirds.net/identification/cackling.html

         http://www.oceanwanderers.com/CAGO.Subspecies.html

         http://www.utahbirds.org/RecCom/NewGoose.htm

         http://www.iowabirds.org/ID/geese.asp

         http://www.texasbirds.org/tbrc/Canadagooset.html

         http://azfo.org/gallery/challenges/WhiteCheekedGeese.html

         http://stokesbirdingblog.blogspot.com/2009/11/cackling-goose-from-every-angle.html


Happy New Year and good birding!

Phil


===================================================
Phil Davis, Secretary
MD/DC Records Committee
2549 Vale Court
Davidsonville, Maryland  21035     USA
301-261-0184
mailto:[log in to unmask]

MD/DCRC Web site:  http://www.MDBirds.org/mddcrc/rcindex.html
===================================================