General principles of parvipes and taverneri identification

• Size is a useless differentiation point
• Plumage is a secondary indicator, with overlap between races
• Bill / head shape and size is a primary indicator, with little to no overlap

See the Subspecies Accounts for each taxon for specific details.

Cautions in identifying and/or separating parvipes and taverneri

• There will be many individuals that are best treated as "Lesser White-cheeked Goose" (either B. h. taverneri or B. c. parvipes). Although companions and association on migration and wintering grounds can sometimes be helpful, this is by no means definitive, even in the Northwest states where taverneri is most expected.
• Plumage variation is such that although potentially helpful (taverneri are more often than not darker on the breast and flanks than parvipes), it is not an absolute indicator. Some parvipes can be fairly dark defuse brownish-tan on the entire underparts, contrary to some published reports that this is always a "lighter colored" race.
• B. h. hutchinsii ("Richardson's" Cackling Goose) is possible in the intermountain West, particularly more so as one moves further east (for instance, southwestern Idaho has occasional birds of this race - see section on B .h .hutchinsii), therefore complicating matters when size is used as an identification criteria, simply because large male B. h. hutchinsii can overlap taverneri and parvipes females.
• Although not a problem when coupled with careful observation and knowledge of the subspecies, a small female B. c. occidentalis ("Dusky" Canada Goose) could be mistaken for taverneri by some, especially when looking at an atypical, slightly lighter plumaged than normal bird, and there are some B. c. moffitti that even more so closely resemble the almost always smaller parvipes, except for bill / head indicators.
• Vocalization differences between the "Lesser White-cheeked Goose" species and larger races of Canada Goose are noticeably different, but simply hearing a higher pitched Cackling Goose type bird does not provide enough id reference to be definitive. The differences between the four subspecies of Cackling Goose are presently little understood and known, although real. More work is needed in this area.