Harlequin duck

A slate-blue and chestnut sea duck that breeds by diving and bracing in fast mountain whitewater instead of calm water.

Harlequin duck at a glance

Histrionicus histrionicus har-luh-KWIN duck; Histrionicus histrionicus is hiss-tree-ON-ih-kus hiss-tree-ON-ih-kus

Type
Bird · waterfowl
Diet
Carnivore
Size
About as long as a school ruler and a half (15 to 18 inches / 38 to 46 cm), and a little heavier than a can of soup (roughly 1 to 1.7 pounds / 540 to 760 grams). Smaller than most ducks you'd see on a pond.
Lifespan
Commonly reported to reach about 10 to 14 years, but banding has documented individuals far older: Glacier National Park researchers identified a banded male at 17 years old in 2013, and the oldest banded harlequin duck on record — a male banded in Alberta in 1995 and resighted in British Columbia in 2014 — reached at least 20 years and 9 months.
Conservation
Least concern (globally, per IUCN); considered imperiled or critically imperiled at the state level across much of the southern edge of its U.S. breeding range, including Washington.

Eats aquatic insect larvae, snails, small fish eggs, crabs and other crustaceans, mussels and snails (winter, on the coast)

On the rivers where it breeds, a harlequin duck dives and dabbles for caddisfly and mayfly larvae, snails, and fish eggs, often bracing against a strong current to hold its place. On its winter coastline it dives into the surf zone for crabs, barnacles, mussels, and other shoreline invertebrates that most ducks won't go near.

Should you worry?

None. A harlequin duck is not aggressive and stays on the water, usually well out in fast current. The real risk runs the other way: these ducks are easily flushed off a nest by people wading, boating, or fishing too close, so keep well back from any duck sitting still along a riverbank in spring or early summer.

The water below Sunrise on the Nisqually River is too rough for most birds to sit in at all, whitewater breaking white over boulders, and in the middle of it rides a small duck painted like nothing else on the river, slate-blue and chestnut streaked with bold white stripes like a mask. It doesn’t fight the current so much as brace against it, diving straight down into the churn and coming back up in almost the same spot.

Finding where a harlequin duck actually nests is so hard that Mount Rainier National Park had exactly one confirmed nest on record between 1920 and 2018, despite decades of biologists looking along its rivers. That changed in 2018, when researchers spotted a female slipping into a cavity along the Nisqually and set up a trail camera. It filmed the ducklings hatching and then leaving the nest on June 23, only the second documented harlequin breeding record at the park in nearly a century.

The reason nests stay so hidden is close to the reason the species can look so battered up close: harlequin ducks breed in pounding rapids and winter diving straight into ocean surf, water rough enough that researchers studying banded and museum birds have long documented an unusually high rate of old, healed bone fractures in the species, a lifetime of collisions few other ducks would survive. A harlequin riding a rapid at Rainier or North Cascades is running the same gauntlet that already broke and mended its bones once.

Did you know?

  • A pair of harlequin ducks can mate for multiple years running. One Glacier National Park male, tracked by his leg band, returned to breed with the same female for three consecutive seasons.
  • Female harlequin ducks tend to breed on the exact stream where they themselves hatched, which is one reason a damaged breeding river can be so hard for the population to recover from.
  • Incubation takes about 28 days, and for most of it the drab, camouflaged female is the only parent involved. Males often leave for the coast before the eggs even hatch.

Common questions

Why is it called a harlequin duck?

For its bold, patchwork markings, blue-gray with white stripes and chestnut patches on the male, like a costume. People sometimes call it the "clown duck" for the same reason.

Are harlequin ducks dangerous?

No. They stay on the water and keep their distance from people. The bigger risk is to them: getting too close to a nesting female on a riverbank can make her abandon the site.

What do harlequin ducks eat?

Aquatic insects, snails, and small fish eggs on the rivers where they nest; crabs, barnacles, and mussels in the ocean surf where they spend the winter.

Where would we actually see one at Olympic, Rainier, or North Cascades?

Scan clear, fast-moving rivers and streams in late spring and summer. North Cascades National Park describes its own rivers as breeding habitat for the species.

How long do harlequin ducks live?

Typically 10 to 14 years, but banded individuals have been documented living into their high teens, and the oldest on record reached nearly 21 years old.

Where it lives

Where we got this