Long-tailed duck (Clangula hyemalis)

Male long-tailed duck (Clangula hyemalis) in winter plumage swimming on calm blue-grey water, pink band on the bill visible
Long-tailed duck (Clangula hyemalis) with distinctive white and brown plumage swims alone on calm open water. Photo was taken at Hokkaido / Japan.

At a glance

Profile

Size

38–60 cm (je nach Geschlecht und Schwanz)

Weight

800–950 g

Way of life

Habitat

Cold coasts, bays, open sea (mainly Hokkaidō)

Diet

Mussels, crustaceans, fish, worms (diver)

Breeding

Not in Japan, 6–9 eggs in Arctic regions · June–August · On the ground near water, well hidden and lined with down

Classification

Scientific name

Clangula hyemalis

Conservation assessment

Threatened worldwide (Vulnerable), not threatened in Japan

Long-tailed Duck – Diving Artist of the North

With its snow-white plumage and striking long tail, the Long-tailed Duck is a fascinating winter visitor to Japan’s northern coasts and bays—built for the icy seas.

Table of Contents

Introduction

This bird seems tailor-made for cold seas—robust yet graceful, with sharp color contrasts that catch the winter light. The Long-tailed Duck is one of the few ducks truly at home on icy oceans, making it a rare but striking sight off Japan’s coastlines during winter.

Appearance – Elegance in Black and White

In winter, the Long-tailed Duck displays a largely white plumage contrasted by dark patches—a color scheme that offers ideal camouflage against snowy and icy backdrops.

  • Males:

– Snowy white body with black face mask, chest, and back
– Extremely long, pointed black tail feather resembling a thin lance
– Pink bill tipped in black, dark eyes

  • Females:

– Softer brown-and-white pattern with a rounded body
– Shorter tail and more subtle facial markings

Both sexes adopt darker, more subdued plumage during the summer months.

Habitat – Icy Coastal Waters

In Japan, the Long-tailed Duck prefers open, vegetation-poor wintering grounds—especially in the far north.

  • Main locations:

– Hokkaidō (most frequent)
– Occasionally in northern Honshū

  • Preferred winter habitats:

– Cold bays, harbors, open coastal sea zones
– Occasionally inland waters with marine influence
– Calm, nutrient-rich areas are favored for foraging

Diet – Diver with Specialized Skills

During the cold season, the Long-tailed Duck primarily feeds on marine bottom-dwellers, diving deep in search of food.

  • Primary prey:

– Crustaceans, mollusks, marine worms, small fish

  • Diving behavior:

Dives up to 60 meters—one of the deepest-diving ducks
– Forages on the seafloor, often in small flocks
– Constantly active and agile in the water

Breeding – Far from Japan

Breeding occurs exclusively in the Arctic tundra—far from Japanese shores.

  • Breeding season: June–August
  • Nesting: On the ground, well-hidden near water, lined with down
  • Clutch size: 6–9 eggs
  • Parental care: Female incubates; young are precocial and leave the nest early

Migration – Wide-Ranging Sea Traveler

The Long-tailed Duck is a true long-distance migrant, traveling thousands of kilometers each year.

  • Arrival in Japan: From November
  • Departure: By April
  • Typical winter locations: Open sea and protected coastal waters

Conservation – Global Concern

  • In Japan: Not considered threatened but uncommon
  • Worldwide: Classified as Vulnerable (IUCN)
  • Major threats:
    – Climate change impacting Arctic breeding zones
    – Oil spills and degradation of marine habitats
    – Disruption by shipping and coastal development

Molting – A Seasonal Transformation

Long-tailed Ducks undergo a striking annual molt that changes both their coloration and silhouette. Males shed their long tail feathers outside the breeding season and regrow them before winter. Their plumage transforms from dark summer tones to sharp black-and-white winter contrasts. These molting periods are often synchronized with migration and take place in sheltered coastal zones.

Visual Description – For People with Sight Impairment

Picture a bird that looks like a brushstroke on water: its body snow-white, contrasting sharply with deep black wings and chest. The male’s long, needle-like tail trails behind like a fine ribbon. Its face features a dark mask, while the bill is soft pink tipped with black.

The female appears rounder and softer, with blended tones of brown and white. Silent and graceful, the duck dives without a splash, staying underwater for long periods before resurfacing with a small mollusk or crab—seemingly born from the sea itself.

Summary long-tailed duck (Clangula hyemalis)

The Long-tailed Duck is more than a seasonal visitor to Japan—it’s a northern specialist, built for frigid seas and long journeys. With its exceptional diving skills and stark beauty, it brings a quiet sense of the Arctic to Japan’s coasts. Its vulnerable global status reminds us of the delicate balance of marine ecosystems and the far-reaching effects of climate change.