[TN-Bird] Re: Lesser Canada Goose?

Doing more reading last night, it seems that bill length and body  
mass  measurements of hutchinsii and parvipes overlap broadly; indeed  
one reference lists the largest hutchinsii as actually bigger than  
the largest parvipes.  There are differences in "typical" head shape,  
but I haven't yet seen an effort to address that rigorously.  I also  
haven't yet found a good discussion of the documented wintering range  
of parvipes.  Both hutchinsii and parvipes winter mostly to our west;  
parvipes farther west on average but both have large populations  
wintering in parts of Texas.  I'm now suspecting those birds I saw  
may be the same ones that Mike Todd saw and photographed in the same  
area earlier in the winter.  The head shapes in his photos do look  
more like what has been described for hutchinsii.  But I am  
increasingly concerned that we don't yet actually know how to  
consistently separate parvipes and hutchinsii in the field, and that  
all but the smallest "Cacklers" seen in Tennessee might not really be  
identifiable to species in the field with current knowledge.  Has  
anyone done DNA on small white-cheeked geese from this area?

The parvipes/hutchinsii/tavernii complex is the fly in the ointment  
for the whole Canada/Cackling split.  They apparently intergrade and  
overlap, and are almost exactly intermediate in size and shape  
between the "true" Cacklers and the "true" Canadas.  Some suspect  
that this split may be redrawn someday soon, with either hutchinsii/ 
tavernii being returned to "Canada" or parvipes being moved to  
"Cackling" (which would take the new sense of "Cackling Goose" even  
farther from the original concept of the smallest races from the  
westernmost areas; maybe it needs to be renamed "Tundra Goose" or  
"Arctic Goose" or something else?).  In the first case (hutchinsii/ 
tavernii/parvipes all lumped with "Canada"), Tennessee and many other  
eastern states might find ourselves without any documented Cackling  
Geese at all anymore.

Bill Pulliam
Hohenwald TN
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