Sooty Grouse (Dendragapus fuliginosus)

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Image of a Sooty Grouse in its natural habitat
Birds Grouse

Introduction

The Sooty Grouse (Dendragapus fuliginosus) is a large forest-dwelling grouse of the Pacific Coast ranges of North America. It occurs from south-eastern Alaska through western Canada and the western United States, including Washington, Oregon and California. The species was formerly grouped with the Dusky Grouse as the Blue Grouse, but the two are now recognised as separate species.

Physical Description

The Sooty Grouse is a heavy, chicken-like bird measuring approximately 40–50 cm in length and weighing about 750–1,300 g. Its short bill, strong legs, broad wings and medium-length tail give it the compact shape typical of a forest grouse.

Adult males are generally dark slate-grey or blue-grey, with darker upperparts and a tail tipped with a broad, pale grey band. During courtship, the yellow to yellow-orange eye combs become more conspicuous, and the male exposes bright yellowish air sacs on the sides of the neck, bordered by white feathers.

Females are smaller and cryptically patterned in mottled brown, grey, buff and white. This plumage provides camouflage while nesting and caring for young. Juveniles resemble females but have a rounder, more fan-shaped tail before acquiring the longer adult tail feathers.

Plumage varies geographically. Birds in the Sierra Nevada of California are often paler grey than those found farther north and west.

Range and Habitat

Sooty Grouse are native to the Pacific coastal region of North America. Their range extends from south-eastern Alaska and British Columbia south through Washington and Oregon to northern and central California, with additional populations in the Sierra Nevada and other montane areas of California.

They are primarily resident birds, although individuals make seasonal movements between habitats. In winter, they commonly use mature, dense conifer forests, where evergreen needles, buds and shelter are available. During the breeding and post-breeding seasons, they also use more open forests, forest edges, shrub-rich clearings, alpine meadows and regenerating areas with abundant grasses and low vegetation.

The species is associated mainly with mountainous coniferous forests, sometimes occurring near sea level in the northern part of its range and at elevations approaching the treeline farther south. Important trees include Douglas-fir, western hemlock, mountain hemlock, Sitka spruce, subalpine fir and other conifers.

Behaviour and Diet

Sooty Grouse spend much of their time on the ground, where they walk slowly while feeding or searching for grit. They also climb and perch in trees, particularly when feeding on conifer foliage or when males are displaying.

Their diet changes seasonally. It includes conifer needles, leaves, buds, flowers, berries, seeds and other plant material, together with insects, especially during the warmer months and when adults are feeding young. Small stones or grit help grind food in the muscular gizzard.

Males establish display territories in spring. Unlike Dusky Grouse, which commonly display from the ground, male Sooty Grouse usually display from elevated perches in trees. A displaying male may make short fluttering flights, fan or raise his tail, expose the yellow neck air sacs and give a series of deep, resonant hoots. The call can carry through dense forest while remaining difficult to locate.

Nesting takes place on the ground. The female makes a shallow scrape, usually under shrubs or other cover, and lines it with nearby leaves, needles, twigs, moss, bark and feathers. Clutches commonly contain about five to ten pale, brown-speckled eggs. The female incubates the eggs and raises the brood without male assistance.

The young are precocial. They hatch covered in down and are able to leave the nest and follow the female soon afterwards. Chicks feed on insects and plant material as they grow, and the female often leads them to open, sunny areas where food is plentiful.

Identification Tips

Look for the following combination of features:

  • A large, heavy-bodied grouse with a short bill and strong legs.
  • A dark grey or blue-grey male with a long, dark tail ending in a pale grey band.
  • A mottled brown, grey and buff female that blends into leaf litter and forest vegetation.
  • Yellow eye combs and bright yellowish neck patches visible on displaying males.
  • Deep, low-pitched hoots, often coming from a high perch in a conifer.
  • Forested mountain habitat, particularly conifer stands with openings, shrubs or meadow edges.

The Dusky Grouse is the most relevant comparison. It occupies much of the interior mountain region and overlaps locally with Sooty Grouse. Sooty Grouse are generally associated with the Pacific coastal side of the mountains and have darker males with yellowish display patches. Their ranges, plumage, vocalisations and display behaviour are useful together when separating the two species. Females of both species can be difficult to identify without close attention to range and habitat.

Conservation Status

The Sooty Grouse is currently assessed as Least Concern globally. It remains widespread, but population monitoring is difficult because the species inhabits remote mountainous forests and its breeding displays occur before or outside the most effective survey periods.

Available survey evidence indicates declines in parts of the range, although the strength and consistency of the trend vary among regions. Important pressures include the loss or fragmentation of mature conifer forest, extensive clear-cutting, development, altered fire regimes and climate-related changes to forest structure, snow conditions and food availability. In some areas, regenerating burned or logged forest can provide suitable breeding habitat, but severe or repeated disturbance may remove the mature conifers needed for winter cover and food.

Conservation measures include retaining mature and old-growth conifers, protecting important breeding areas, maintaining a mixture of forest ages and openings, improving monitoring methods, and managing habitat at landscape scale. Sustainable hunting regulations and protection of nesting and brood-rearing habitat are also relevant to local population management.

Frequently Asked Questions

Where does the Sooty Grouse live?

It lives in coniferous forests and associated clearings across the Pacific Coast ranges of North America, from south-eastern Alaska and British Columbia to California.

Is the Sooty Grouse migratory?

It is generally resident rather than long-distance migratory. Individuals make seasonal movements between open breeding habitat and denser conifer forest, and some populations shift in elevation during the year.

What does the Sooty Grouse eat?

Its diet includes conifer needles, leaves, buds, flowers, berries, seeds and insects. The balance of plant and animal food changes with the season and the age of the bird.

How can a male Sooty Grouse be identified?

A male is usually dark slate-grey or blue-grey, with a pale grey tail band. During courtship, his yellow eye combs and yellowish neck air sacs become conspicuous, and he gives deep hoots from a tree perch.

Where does the Sooty Grouse nest?

The female builds a shallow ground nest, usually beneath shrubs or other overhead cover. She incubates the eggs and raises the chicks alone.

Is the Sooty Grouse endangered?

No. The species is currently classified as Least Concern globally, although habitat loss and possible population declines in some regions remain conservation concerns.

References

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