How to identify the Black Grouse

To correctly identify the Black Grouse (Tetrao tetrix), check each of these features. Birds can be tricky: habit, habitat, and call often confirm a sighting that a single photo cannot.

Size at a glance

Length

Male: 49-58 cm; Female: 40-45 cm

Wingspan

Male: 75-80 cm; Female: 65-70 cm

Weight

Male: 1000-1700 g; Female: 750-1100 g

Physical features to check

1. 1

   Plumage

   Overall feather coloration and pattern.

   Adult male: Glossy blue-black plumage with a distinctive lyre-shaped tail, prominent red wattles above the eyes, and white undertail coverts. Adult female: Cryptic barred brown and black plumage, with a slightly forked tail and smaller red wattles (often less visible).

2. 2

   Beak shape

   Shape and color of the bill: a key field mark.

   Short, stout, conical beak, adapted for browsing vegetation. Dark grey to black.

3. 3

   Eye color

   Iris color and any distinctive eye markings.

   Dark brown.

4. 4

   Leg color

   Leg and foot color.

   Greyish-brown, feathered down to the toes.

5. 5

   Distinguishing features

   Standout features that separate this species.

   Male's lyre-shaped tail and white undertail coverts are unmistakable. Female's overall barred brown appearance with a pale wing bar (visible in flight) and slightly forked tail distinguishes her from other grouse species.

6. 6

   Juvenile appearance

   How young birds differ from adults.

   Juveniles resemble females but are generally duller, with finer barring and less distinct markings. Young males gradually acquire black feathers and develop the lyre-shaped tail and red wattles over their first year.

7. 7

   Seasonal changes

   Plumage variation between breeding and non-breeding seasons.

   No significant seasonal plumage changes in adults, though the red wattles of males become more prominent and intensely colored during the breeding season.

8. 8

   Sexual dimorphism

   How males and females differ.

   Highly sexually dimorphic. Males are significantly larger, entirely glossy black with prominent red wattles and a lyre-shaped tail. Females are smaller, cryptically camouflaged in barred brown and black, with a less pronounced tail shape and smaller wattles.

Key field marks

• Male Plumage. Look for the glossy blue-black body, prominent red wattles above the eyes, and the unmistakable lyre-shaped tail with white undertail coverts.
• Female Plumage. Observe the cryptic barred brown and black plumage, a slightly forked tail, and a pale wing bar visible in flight. She is smaller than the male.
• Lekking Behavior. During spring, listen for the bubbling 'rookoo-roo' calls and watch for males displaying in open areas at dawn and dusk. This behavior is unique and highly diagnostic.
• Habitat. Search in mosaic habitats of open woodlands, moorlands, bogs, and forest edges, particularly where birch and willow are present.
• Flight. Note the strong, direct flight with rapid wingbeats and glides, often accompanied by a whirring sound.

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