17-Year Old Harlequin Duck Identified in Glacier

WEST GLACIER, MONT. – A male harlequin duck, known to be at least 17 years-old, was recently identified in Glacier National Park by University of Montana researchers and Glacier National Park scientists. The banded duck is believed to be the third oldest on record. 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,” said Lisa Bate, Glacier National Park Biological Science Technician. “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.”

In 2011, a study of harlequin ducks on Upper McDonald Creek was initiated by Glacier National Park in cooperation with researchers from the University of Montana. Researchers use radio-telemetry and banding to learn more about the location of harlequin nests and factors affecting offspring survival. Upper McDonald Creek is considered an important breeding stream for harlequin ducks, comprising 25% of known broods produced in Montana. The area also has the highest density of breeding harlequins in the lower 48 states. Glacier National Park has approximately 40 pairs of harlequins in the park.

Harlequins are small sea ducks that spend most of their lives along the coastal waters of North America. 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.

While the harlequin duck study within Glacier National 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.

This project was funded by the Federal Highway Administration, University of Montana, grants provided through the National Park Service Rocky Mountains Cooperative Ecosystem Studies Unit, and Glacier National Park Conservancy.