Dusky Canada Geese
The Willamette Valley National Wildlife Refuge Complex was established
in 1964 to protect wintering dusky Canada geese.
What is a dusky Canada goose?
The dusky is a subspecies of Canada goose that breeds only in the
Copper River Delta area on the south-central coast of Alaska and
on islands in the Prince William Sound and Gulf of Alaska. They
winter primarily in the Willamette Valley and along the lower Columbia
River of Oregon and Washington. The dusky has one of the smallest
populations of geese in North America.
When are duskies seen in the Willamette Valley?
In the fall duskies migrate south along the Pacific coast, arriving
at their wintering grounds of southwest Washington and western Oregon
in October and November. Here they feed on nutrient-rich grasses
that grow in the wet, mild winters until they depart in early April.
Why were the Willamette Valley refuges established for the dusky
Canada goose?
In the late 1950s, managers recognized that wintering habitat for
duskies was limited and hunting needed to be restricted to protect
duskies. At that time, duskies made up about 2/3 of the geese in
the Willamette Valley, and it was recognized that the area was essential
to their winter survival.
What are other threats to the dusky Canada goose?
Habitat changes throughout the wintering and breeding areas have
contributed to declines of duskiness. In March 1964, at about the
time the refuges were being established, a major earthquake lifted
the Copper River Delta 2 to 6 feet. Since that time, the uplifted
area has changed from tidal wetlands to uplands, and open habitat
has become increasingly closed as trees and shrubs have quickly invaded
the area. Predators such as bears, foxes, and other mammals have
become more common in the breeding area. Increased cover for these
predators also makes it easier for them to prey on geese and their
eggs.
What is being done to protect the dusky Canada goose?
The establishmeAugust 29, 2008protects winter habitat for duskies. Duskies tend to congregate
around the refuges, which provide wetlands for roosting and grass
fields for food for the geese. Hunting was banned from the refuges
in the mid-1980s to protect duskies. Disturbance to geese is limited
by closing areas of the refuges between October and April when the
duskies are here. In addition, hunting restrictions have been put
in place in areas where duskies commonly occur.
Is it legal to hunt dusky Canada geese?
Without protection, duskies would be more vulnerable to hunting
than other subspecies because of their behavior. Duskies feed in
smaller fields and fields with fewer geese than other subspecies
of Canada geese. They approach lower and circle less before landing
in a field. Currently there are restrictions to discourage the harvest
of duskies. Hunters in the area used by duskies must take a goose
identification test to get a license to hunt geese. Hunters must
check their geese at goose check stations in the area to determine
what subspecies of goose were killed. If a hunter kills a dusky,
the hunter is not allowed to hunt for the remainder of the season.
Once a quota of duskies is reached for the region, the goose season
is ended.
What other kinds of geese are found here?
Currently, dusky Canada geese make up approximately 10% of the geese
in the Willamette Valley during the winter. The Willamette Valley
is also the wintering home for the cackling, Taverner’s, lesser,
and western subspecies. The Aleutian and Vancouver subspecies may
also rarely be found here. These were all considered to be one species
of Canada goose until 2004, when the American Ornithologists’ Union
determined that small-bodied geese were a distinct species from the
large-bodied geese. Taverner’s, cackling, and Aleutian subspecies
were placed into the new cackling goose species, with the other subspecies
remaining Canada geese. All have similar brownish coloring and pattern
with black head and neck and white cheeks, but may have subtle differences
in size, shape, and coloring.
Greater white-fronted geese migrate through the area in fall and
spring, and may occasionally be found among other geese during winter.
Brant, Ross’ and snow geese are also rare visitors here.
What kinds of geese were found here in the past?
In the 1800s, ornithologists described geese that were apparently
lesser or Taverner’s and western Canada geese in the Willamette Valley.
Early records indicate that duskies wintered in coastal areas of
Oregon and Washington. By the 1950s, 2/3 of the geese in the Willamette
Valley were duskies. During the mid-1960s, this figure increased
to more than 90%. By the early 1970s, other subspecies of geese
were using the area, and by the late 1970s, 85% of the geese in the
valley were lessers and Taverner’s. The numbers of western Canada
geese have also increased since then. During the 1990’s, the majority
of cacklers, which had previously wintered primarily in the Central
Valley of California, shifted their wintering grounds to western
Oregon. Although the population of cacklers has been declining,
numbers wintering in the Willamette Valley increased during the 1980s
and 1990s. Cacklers currently make up about 80% of the wintering
flocks. Although duskies were formerly the majority of the approximately
25,000 geese that wintered here, they now make up less than 10% of
the 250,000 geese in the valley. Taverner’s and lessers account
for approximately 10-15%. A small fraction of the wintering geese
belong to the western subspecies, which is a local resident and the
only type of goose that breeds in the Willamette Valley. A small
number of Vancouvers have regularly wintered here, but population
trends are unknown as these birds are nearly identical to duskies.
What do geese eat?
In the Willamette Valley, wintering geese eat mostly grass that
is grown for grass seed. They also eat other crops such as corn
and other grains, and may feed in pastures. Grass grows during the
mild, wet winters and provides a nutritious food for the hungry geese.
Grass seed farming has increased dramatically in the last 50 years
and along with it the number of geese wintering here.
How do I tell which geese are duskies?
The dusky is a medium to large, dark subspecies of Canada goose.
They have darker backs and breasts compared to other subspecies in
this area. Some duskies may be wearing red neck collars with white
letters. Duskies are often found in small groups by themselves or
mixed with other subspecies.
Why are there neck collars on some of the geese?
Some geese are captured on their breeding grounds and collared with
colored neckbands inscribed with a unique combination of letters
and numbers. Each subspecies has its own distinct color for neckbands.
Dusky collars are red with white letters or rarely green with white
letters. Ratios of duskies marked with colored neckbands to unmarked
duskies are determined from samples of geese observed during two
resighting periods. A population estimate is developed by expanding
the total number of recorded marked individuals by a factor for the
unmarked proportion of the population.
How is the population doing?
Duskies were at their lowest known numbers in the mid-1950s, when
only about 5,000 were counted on the wintering grounds. The population
increased and reached its highest level at around 20-25,000 in the
late 1970s, then decreased to 12-14,000 in the 1990s. The most recent
surveys have found between about 15,000 and 20,000 wintering duskies.
During the winter of 2004-2005, the dusky population was around 22,000.
