By Elliott Deins
The Alaska Department of Fish and Game, U.S. Forest Service Cordova Ranger District, and Ducks Unlimited conducted dusky Canada goose banding on the Copper River Delta and Martin Lake last month.
As researchers crouched behind bushes, the chopping sound from the blades of the helicopter was drowned out by the honks from hundreds of molting geese waddling their way through a constructed net funnel and into a pen.
Over 400 duskies (Branta canadensis occidentalis) were herded by helicopter, corralled, banded, fitted with neck collars, and released safely.
“The primary objective for the banding and collaring is to estimate annual survival through a mark-resight analysis,” said Brandt Meixell, lead wildlife biologist for the Cordova Forest Service. “The birds are marked here, then they’re resighted both here and on the wintering grounds in Washington and Oregon.”
The resighting data, banding data, and recapture data helps researchers estimate and understand the trajectory of the population and identify potential limiting factors of population growth. Four hundred and fourteen birds were given bands, and 102 were recaptured from previous years.
“Dusky migration and population are a focus of the Pacific Flyway Council,” said Jasone Schamber, waterfowl program director with Alaska Department of Fish and Game.
Schamber went on to describe how the council utilizes resources across multiple states to monitor duskies for the purpose of protecting and conserving migratory birds inhabiting western North America.
“We certainly rely on the Forest Service heavily to help out with equipment and personnel needs,” Schamber said. “That partnership is necessary in pulling off the banding, but we try to invite flyway involvement as much as we can, simply because duskies are a shared management resource.”
According to Meixell, this year’s 300-band objective was a challenge to meet but it was, ultimately, a good problem to have.
“It was a good year for production,” he said. “We target adult molting flocks that are either made up of failed breeders or birds too young to nest. The successful breeders are hanging out with their goslings in group flocks. We don’t target them to not risk negative effects on the goslings.”
The banding takes place while the birds are molting, the process of shedding and regrowing flight feathers. The molting birds come together in flocks ranging from hundreds to thousands.
Historically, the Copper River Delta has been the perennial breeding grounds for the dusky Canada goose. However, when the land rose five to 11 feet after the 1964 Alaskan Earthquake, so did wooded vegetation and natural predators like bears, wolves, and eagles causing the dusky population to dwindle.
Artificial nest islands were implemented by the Forest Service. Banding and collaring helps to ensure dusky management is on track with a goal of 20,000 birds.
Through the efforts of the Forest Service and other organizations across multiple states, the dusky population has stabilized and continues to rise on the Copper River Delta.
This article was submitted by the Wildlife/Ecology/Forestry program of the Cordova Ranger District, Chugach National Forest.
