Glacier Park harlequin duck is 17 years old

Glacier National Park has a teenager among its wildlife ranks. But this is no ordinary adolescent. It’s a male harlequin duck.

Park biologists last week said a banded male harlequin duck they captured and released as part of a research project was at least 17 years old. The oldest known banded harlequin duck has a recorded age of 18 years and 10 months.

“Prior to these findings, harlequin ducks were reported to live up to only 10 years of age, which makes this finding a positive indicator of the health and longevity of harlequin breeding populations in Glacier National Park,” Glacier National Park biological science technician Lisa Bate said. “Research indicates harlequin ducks mate for life unless something happens to one member of the pair. This old male has returned the last three years with the same female.”

Park biologists discovered the banded duck while doing harlequin research along upper McDonald Creek.

Researchers have been using radio-telemetry and banding to learn more about the location of harlequin nests and factors affecting offspring survival since 2011. Upper McDonald Creek is considered an important breeding stream for harlequin ducks, comprising 25 percent of known broods produced in Montana. The area also has the highest density of breeding harlequins in the Lower 48.  About 40 pairs of harlequins inhabit the Park.

Harlequins don’t just breed in McDonald Creek, but with its easy access along the Going-to-the-Sun Road, it's the best place to see the unique duck.

Harlequins are small sea ducks that spend most of their lives along the coastal waters of North America. Unlike most ducks, they migrate from west to east each spring and then back to the coast after raising their young. The males leave soon after they mate, but the females stay and raise the brood and then migrate back to the coast in the fall.

Living to teen years is a feat in itself — the ducks are subject to limited hunting while living in the ocean. In Washington, hunters are allowed to shoot one harlequin per season. In addition, a host of predators eat ducks. Bald eagles dine on adults and chicks, and land predators like mink, bears, fox and coyotes will all eat the eggs and young chicks if they can find them.

Male harlequins are slate blue with bold white, black, and chestnut highlights. They are often referred to as “clown ducks” for their unique coloring and markings. Female harlequins are brown and gray, which allows them to blend into their surrounding while they sit on their nests for 28 days.

Each spring, harlequins migrate inland to breed and raise their young along fast-moving, freshwater streams. They are considered to be more strictly confined to running water than any other waterfowl species breeding in the Northern Hemisphere.

Harlequins are slow to mature, sensitive to human disturbance and vulnerable to climate change because they select nest sites close to the water’s edge. Female harlequins only breed on the streams where they were born, making the integrity of breeding sites especially important to maintain populations. The state of Montana lists harlequin ducks as a species of special concern.

Glacier Park visitors are reminded to view all wildlife at a distance and not disturb wildlife in any way, and they’re also encouraged to report to the Park any observance of harlequin ducks on streams in the Park other than Upper McDonald Creek.

While the harlequin duck study in the Park will conclude this fall, scientists throughout North America will continue to survey and collect information from banded harlequins. A University of Montana graduate student is expected to publish a thesis regarding the Park study near the end of this year.

The $50,000 study was funded by the Federal Highway Administration, University of Montana, and grants provided through the National Park Service Rocky Mountains Cooperative Ecosystem Studies Unit and the Glacier National Park Conservancy.