During the first half of the 20th century,
migratory geese were captured for use as live decoys. The resident Canada geese
in are the descendents of these captive migratory geese. The captured geese,
flight feathers clipped, sometimes with light weights on their legs, lured
other migratory Canada geese into lakes, wetlands and rivers during the great
Canada geese migrations in the spring and fall. These captive geese were also bred in captivity. As a
consequence, their descendents do not have biological need to migrate to Canada
since geese nest in the area where they were born.
The near extinction of Canada geese populations - Creating
the current conflict
By the early 1960’s, because of the increased hunting
efficiency resulting from the use of these live decoys, the migratory Canada
geese population was threatened with extinction and the resident flocks were
mostly gone. To counter this near
extinction, the US Fish and Wildlife Service and many State wildlife agencies
began a program of re-population of wild Canada geese. They did this by taking
the eggs from the nests of the surviving resident Canada geese and artificially
incubated these eggs while the geese laid another clutch (double clutch).
Nesting enhancement technologies, such as nesting tubs which raised nests above
ground, further increased the recovery by reducing predation of nests by other
wildlife. By the early 1990’s this
re-population effort was halted because it resulted in large resident geese
populations in cities and suburban areas.
The resident Canada geese population
Unfortunately, the geese born as a result of the Canada
geese repopulation effort do not have the imperative to nest in Canada since
they are born here. Resident geese
nest here, where their ancestors were forced to nest. And since the climate is
temperate in our area and the water bodies do not freeze for long periods of
time, the resident Canada geese have no need to fly south to find open water
and grass in the winter. Although in harsh weather they will fly south for the
short periods of time needed to find open water. Migratory geese nest in Canada
because that is where they were born.
Even when it is 10 degrees Fahrenheit, as long as the geese
can find open water, they stay warm. The water is 32 degrees and the geese have
down on their bellies and chest which insulates them from the cold water.
Resident Canada geese nest in the early spring and have
their goslings in May. They must stay in the area to protect and raise their
goslings. The goslings cannot fly
until mid to late August well after their parent geese molt which begins in
June. Therefore, the geese with
goslings and the goslings are biologically “trapped” in the area where they had
nested and then subsequently molted.
Canada geese under three years of age (juveniles) do not
nest, although they will pair up.
These juvenile geese and adult geese with and without goslings leave
their nesting areas to a safe location to molt (naturally lose flight
feathers). This generally is an area which has a water body for sanctuary and
nearby grass for food.
Canada geese and goslings are very vulnerable to land predators during
the molt and need a water body for sanctuary. Compounding the situation other geese that may have nested
in nearby areas walk their goslings to sensitive areas like parks and school
grounds and molt there. Also, some juvenile geese (non-nesters) from other
places in the neighboring counties who are looking for a good place to nest and
molt may pick a water body in the program area.
The geese that do not “molt migrate” and goslings cannot
leave until early to mid August when they are again able to fly. Until then, they
are trapped because they are flightless. This is a cause of frustration with
Canada geese because it seems no matter what one does they do not leave. In
fact, they cannot. Unfortunately, this period coincides with the start of the
spring active outdoor activities and continues into summer vacation times when
people are out in parks.
Fortunately, resident Canada geese without goslings
(juveniles and adult geese with failed nesting) have an option to find a
distant place to molt, before they
are biologically trapped in the area.
When geese without goslings leave their nesting area it is called a
“molt migration”. Sometimes this
molt migration, which begins in early June, can take the geese hundreds of
miles away. This has been
confirmed by studies on molt migration conducted by Cornell University and the
Michigan DNR. They placed satellite tracking devices on geese without goslings.
Theses geese left their local nesting areas in early June and did not return
until late September. They molted in James Bay, in Canada.
Also, during the months of September through February,
resident Canada geese fly from pond to pond so they are aware of many possible
good areas to molt, many of which do not cause problems for communities.
Why do resident geese go on a molt migration?
Geese have a built in mechanism to fly north in the spring
(iron in the beak helps them navigate – a built in compass). Canada is a much better place to molt
because of the longer daylight hours in the spring and summer and abundant
water and grasslands.