
With the recently published 45th supplement to the Check-list
of North American Birds the American Ornithologist's Union's
Committee on Classification and Nomenclature (Banks et al. 2004)
split the Canada Goose (Branta canadensis) into two species:
Canada Goose (B. canadensis) and Cackling Goose (Branta
hutchinsii). The larger subspecies are included under B.
canadensis with the smaller subspecies included under B.
hutchinsii.
In Texas, both of these species occur in the state and are relatively common in some areas. With this change in taxonomy there will, of course, be greater scrutiny on these birds and there is much to be learned about the distribution and relative abundance of Cackling Goose in particular. There are several subspecies of B. canadensis known (or believed) to occur within the state. Here is a breakdown of those subspecies:
B. c. interior
This is a large subspecies that is thought to be an uncommon migrant
and winter resident in eastern half of the state and along the
coastal plain.
B. c. moffitti

This is another large subspecies that is lighter in overall body
plumage than B. c. interior. Moffitt's is also thought
to be an uncommon migrant in central and eastern Texas and an
uncommon winter resident along the coast. Grieb (1970) stated
that this subspecies constituted a small percentage of the birds
wintering in the Panhandle, however that wintering population
has undergone tremendous growth in the past three decades and
the current makeup of the population may be different.
B. c. parvipes

This subspecies is also known as the Lesser Canada Goose and is
medium sized and proportioned. Grieb (1970) stated that 90-95
percent of the birds wintering in the Panhandle consisted of this
subspecies. They are also thought to be rare migrants elsewhere
in Texas and rare in winter on the coastal prairies. This subspecies
is intermediate in size between the larger subspecies listed above
and the Cackling Goose.
The Cackling Goose subspecies found in Texas is primarily B. h. hutchinsii. However others have been reported as follows:
B. h. hutchinsii

This subspecies is a common migrant in central and eastern Texas
and a common to uncommon winter resident along the coastal plain
and in the Panhandle and South Plains. This small goose is pale
in overall body plumage.
B. h. minima Ridgway
There is one documented record of this subspecies (a specimen
from Kleberg County) and a couple of other sight records that
are thought to pertain to this subspecies. B. h. minima
are much darker in overall body plumage than B. h. hutchinsii.
B. h. taverneri
This is a medium-sized subspecies. There are specimens from Irion
and Waller Counties and the subspecies is generally thought to
be a rare to very rare migrant and winter visitor to Texas. Considering
the range of the subspecies (breeding in western Alaska and wintering
on the Pacific Coast), they are likely a very rare visitor at
best. How this subspecies can be separated from Canada goose is
unknown to me at this time.
There are likely to be identification problems with some "Canada" Geese seen in Texas simply because all three "sizes" of birds occur in numbers in the state. Large individuals of the largest subspecies of Canada Goose (B. c. interior and B. c. moffitti) should be readily identifiable, as should the smaller Cackling Geese. However, "Lesser Canada" Geese (B. c. parvipes) appear to overlap significantly with both the larger Canada subspecies and Cackling Goose. Certainly more information about these birds will be forthcoming and this identification dilemma will be lessened in the next few years, but for now, caution is advised when looking at intermediate sized Canada-type geese. Furthermore, the Check-list Committee suggested that further taxonomic revisions maybe forthcoming. This would suggest that careful examination of Canada-type geese in an attempt to identify subspecies (or subspecies groups) may be of further value in the not-too-distant future.
The Texas Cooperative Wildlife Collection at Texas A&M
University contains these specimens: B. h. hutchinsii from
Waller and Wharton Counties; B. h. taverneri from Irion
and Waller Counties; B. c. parvipes from Waller County.
These were confiscated in 1969 from a
hunter in Waller County and were identified by John Aldrich, then
of the USFWS and the U.S. National Museum.
Literature Cited
Banks, R. C., C. Cicero, J. L. Dunn, A. W. Kratter, P. C. Rasmussen, J. V. Remsen, J. D. Rising, D. F. Stotz. 2004. Forty-fifth supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 121:985-995.
Grieb, J. R. 1970. The shortgrass Canada goose population.
The Wildlife Soc. Monogr. 22. Washington, D. C.
Mark Lockwood
Secretary, Texas Bird Records Committee
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