New Kid on the
Block
(This 732nd Buffalo Sunday News column was first published on April
10, 2005.)
Bird watchers love to keep lists: life lists, state and county lists,
year lists, big day lists. So the appearance of a new bird in the region
attracts much attention.
A brand new
species is here now, ready to be added to any or all of those lists. Its name
is cackling goose.
This addition is
different from rare birds like the cave swallow and lark bunting that showed up
here recently. It is a species newly separated by American Ornithologist Union
taxonomists from a similar appearing common species, the Canada goose. As Ken
Abraham of the Ontario Ministry of Natural Resources says, "Nothing has
changed except the name! Cackling geese did not suddenly become more abundant
here, they didn't change their migration route to accommodate our life lists,
and they don't know that they're being watched more closely." They have,
in fact, been around all along.
But now this
taxonomic decision means that they can be counted.
You know how to
identify Canada geese. Until twenty years ago we knew them simply as beautiful
birds. They have a black head and neck broken only by a distinctive white chin
strap. They often fly in V-formations and their honking arrival was one of the
most pleasant signs of spring.
Unfortunately,
many of those geese have become permanent residents and now spend their time
soiling and gouging golf courses and other suburban lawns. Others have become
tame and beg for handouts. As a result, our favorable view of Canada geese has
been compromised.
There are still
migrant Canada geese, however, and among them are a few much smaller birds.
Those are the cackling geese. Seen with their larger relatives, they appear
scarcely more than duck-sized. In overall mass the cackling geese that appear
here are only about 3/4 the size of Canadas. But the best field mark is the
cackling goose's bill. It looks like a snub nose next to the big schnoz of the
Canada.

For some years
birders had been identifying a small Canada goose subspecies during migration
periods. It went under the common names: Hutchins's or Richardson's goose.
Those same birds are now cackling geese.
Field Guide
writer David Sibley summarizes how these birds compare with the larger Canadas:
"much smaller with a short, stubby bill, relatively round or even square
head with steep forehead (vs wedge-shaped head), and relatively short
neck." There are also minor color differences and the cackling goose's
voice is slightly higher pitched.
The source of
this change brings taxonomy close to contemporary TV crime shows and real life
events like the O. J. Simpson trial. Both taxonomists and forensic
criminologists use mitochondrial DNA for identification purposes. While the
crime investigators look for similarities, taxonomists look for differences.
And although individual changes occur as chance events, they accumulate over
time regularly and give a measure of when different organisms separated
genetically. In the case of cackling geese, taxonomists found that they split
from their larger Canada geese relatives at least a million years ago.
Thus a cackling
goose is indeed a different species and deserves its newfound status.
Unfortunately,
that does not complete the picture. Despite those DNA differences, birders have
neither the equipment nor the opportunity to apply forensics in the field. And
problems can arise. Younger Canadas are smaller as are birds that have had
limited food resources on their breeding grounds. Abraham warns, "We are
left with identifying cackling geese on poorly quantified and often vague
descriptions of size, shape and color."
Despite these
problems, some of our top local birders are picking out a few cackling geese
from among the half million Canada geese currently migrating through western
New York.
If you visit the
Iroquois-Tonawanda-Oak Orchard Wildlife Refuge complex, the ponds that appear
below the escarpment parallel to and just south of Route 5 or the shores of
Lakes Erie or Ontario, keep an eye out for a few smaller Canada geese
look-alikes. There is a good chance that those are cackling
geese.-- Gerry Rising