Resident maximas and migrating interiors
All geese are not created equal. Those wreaking the most havoc in
Toronto are the largest subspecies of Canada goose — the giant
Canada goose (Branta canadensis maxima). They are also known
as resident geese since they breed and nest locally. When Toronto
freezes over, some migrate to the slightly warmer American side of
Lake Ontario or outside city limits where harvest leftovers lie in
fields. After the spring thaw, many resident geese that are old
enough to fly but too young to breed as well as some failed breeders
— all known as moult migrants — head to James Bay for the summer.
There is only one recognized species of Canada goose, but there
are enough differences among North American populations that
biologists distinguish anywhere from 11 to 188 subspecies — an issue
“scientists have argued about for 50 years,” says Jim Leafloor, a
waterfowl biologist with the Ontario Ministry of Natural Resources in
“The birds encounter different environments depending on where
they were raised,” says Leafloor. “They adapt to local environments
and thus look different.” In general, he says, Canada geese are
largest in southern populations and become progressively smaller in
Some conservation biologists agree that hunting is the most
effective way to decrease overabundant wildlife populations, so some
regions are changing the timing of their hunt to coincide with the
movements of giant Canadas. In Ohio and Michigan, for example, bag
limits for Canada geese were raised early in the hunting season to
target giant Canadas, and early goose seasons have been established
in southern Ontario for the same reason.
Some migrant populations, such as the slightly smaller subspecies
B. canadensis interior, are decreasing since they face growing
competition in their summer nesting range along southern James Bay.
Already scarce food resources are being depleted by unprecedented
snow goose populations (Anser caerulescens) and, to a lesser
degree, by giant Canada goose moult migrants. Increased hunting of
northern birds may further diminish migrant geese in central North
America. But many people wonder whether we should care. There seem to
be enough Canada geese around that their survival as a species is far
Leafloor says it is important to conserve subspecies since greater
variety can help the long-term survival of the species as a whole.
"Diversity is good since more diverse populations can withstand
— Elizabeth Shilts
|Modified from original by Steven Fick/Canadian Geographic|
A. Southern James Bay geese: Migrants wintering in the United States move
north via the Mississippi and Atlantic flyways bound for
summer nesting grounds around James Bay.
B. Toronto moult migrants:
Some Toronto-area geese move to James Bay for summer
Toronto-area breeders occasionally leave the city for rural
Ontario, or to overwinter in the U.S.
D. U.S. moult migrants:
Some geese from the northeastern U.S. migrate to
southern Ontario for summer moulting.
(This article first appeared
in Canadian Geographic magazine, May/June
1998. It may not be reproduced without written permission