Spruce Grouse


Spruce_GrouseThe Spruce Grouse is a forest dwelling bird that dwells in coniferous forests throughout the northern regions of North America. Recent evidence suggests that the spruce grouse is declining across its range in New York State. A better understanding of the habitat that this species relies on is necessary to prevent future declines as forests in this region change over time.

The spruce grouse or Canada grouse (Dendragapus canadensis) is a medium-sized grouse closely associated with the coniferous boreal forests or taiga of North America. It is one of the most arboreal grouse, fairly well adapted to perching and moving about in trees. When approached by a predator, it relies on camouflage and immobility to an amazing degree, for example letting people come to within a few feet before finally taking flight, a behavior that has earned it the moniker “fool hen”. It is present in Quebec and its French name is “tétras du Canada”.

Spruce Grouse

Spruce grouse are 38–43 cm (15–17 in) long; males weigh 550–650 g (19–23 oz) and females 450–550 g (16–19 oz). Races vary slightly in plumage, especially in the tail pattern and in the extent of white on the underparts, but in general adult males are mainly grey above and black below, with white spots along the side, and a red patch of bare skin over the eye. Adult females are mottled brown (red morph) or mottled grey (grey morph) with dark and white bars on the underparts. Juveniles resemble females. Females may be confused with ruffed grouse but they have a dark tail with a pale band at the end (while the reverse is true in ruffed grouse) and they do not erect their crown feathers when alarmed the way ruffed grouse do.

Project:
Spruce Grouse Distribution, Movements, and Habitat Selection: A Mid-Successional Species in an Aging Landscape

Summary: In this study, I examined the influence of habitat structure and composition on the distribution and movements of spruce grouse. I surveyed previously occupied (n = 30) and potentially occupied (n = 25) lowland coniferous forest patches for spruce grouse throughout the northern Adirondack Park Region. Grouse were observed at approximately half (n = 13) of the sites occupied from the period of 1976-1987 and at one new site. Greater amounts of black spruce (Picea mariana) scrub/shrub vegetation were found within home ranges ( = 21.9 %) versus random conifer patches ( = 3.5 %) (p = 0.001). Stand characteristics at spruce grouse sites with persistent versus extirpated populations consisted of significantly younger ( = 45 versus 53 years respectively, p < 0.001) and shorter trees ( = 11.2 versus 12.5 m, p < 0.005), more live foliage cover in the 0.2-1.0 m range of the vertical strata ( = 59.7 versus 36.3 %, p < 0.001) and more coniferous ( = 30.4 versus 18.7 %, p < 0.001) shrub cover, but less balsam fir (Abies balsamea) shrub cover ( = 3.8 versus 11.6 %, p < 0.001) than extirpated sites. Occupied conifer patches were closer to other occupied patches than extirpated patches were to occupied patches. Findings support the ideas that (1) successional changes in the lowland boreal forest as well as (2) spatial arrangement of these patches in New York may influence spruce grouse site occupancy.

Location: Northern New York

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