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.