Yesterday we visited Blue Mash Nature Trail just before dusk.  On the 
pond there was one very small goose that in my 2003 Sibley would have 
been a Richardson's based on size.  We viewed it in good light and from 
not far away.  It was the size of a large duck, and the neck was much 
shorter than that of a normal Canada.  We observed it swimming and 
walking.  It did not make any sound.  The only other bird in the area 
was a Great Blue Heron.  My own guess about the bill is that it was of 
the same proportions as a Canada, while my wife, who is very observant 
but does not claim to be a birder, thought it was stubbier.

Does size alone make this now a Cackling Goose?  Does location and time 
of year add any value?

I found a web page by Sibley that started to list the identification 
issues, but they are quite complex and neither my Yellowbook nor my 
Sibley book is any help here.  Expert guidance appreciated.

Thanks,

Gary Ender
Bethesda MD