Archive for category birds

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.

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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Rusty blackbird

Rusty BlackBirdThe Rusty Blackbird (Euphagus carolinus; RUBL) experienced one of the most significant declines ever documented among a once-common North American bird. Recent research on RUBLs has yielded information about the basic ecology of this understudied coniferous wetland breeder, but the critical factors responsible for their precipitous decline (> -90%) and their failure to recover remain unknown. One factor may be an “ecological trap” where birds nest in regenerating logged areas adjacent to wetlands (Powell et al. 2010) and are exposed to disproportionately high nest predation compared to wetlands in unharvested forest. Timber harvest likely affects abundance and diversity of nest predators.

The rusty blackbird (Euphagus carolinus) is a medium-sized blackbird, closely related to grackles (rusty grackle is an older name for the species). It is a bird that prefers wet forested areas, breeding in the boreal forest and muskeg across northern Canada, and migrating southeast to the United States during winter.

Formerly abundant, the rusty blackbird has undergone one of the most rapid declines of any abundant bird species in North America in recent years, for reasons that are not well understood.

Project Title: Will an ecological trap prevent the recovery of the Rusty Blackbird in Northeastern North America?

To address this issue, we propose to study the nesting ecology of and nest predation rates in the Rusty Blackbird throughout the Northeastern United States. The project goal is to evaluate what role an ecological trap may have on the potential recovery of the species in the northeast. We have four objectives:

Determine the primary predators on bird eggs and nestlings
Compare abundance and diversity of predators and nest predation rates in wetlands adjacent to regenerating clearcuts and adjacent to unharvested forest
Identify stand- and landscape-level habitat variables that influence nest predation rates between these two habitats
Identify linkages between predation, competition, habitat and other factors such as climate change to permit inferences about the likelihood of recovery for this species across our region.

Location: Various locations throughout Maine, Vermont, New Hampshire and New York

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