Ruffed Grouse (Bonasa umbellus) Conservation Status Review
Review Date = 01/15/2009
ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment220397 square kilometers based on Natural Heritage Program range maps
Area of Occupancy
ScoreH - >20,000 km squared (greater than 5,000,000 acres)
Comment61,517 square kilometers based on GAP predicted model.
ScoreE - Relatively Stable (±25% change)
CommentDry Conifer Forest habitats with shrub cover have remained stable, although there have declines in aspen. Overall habitat is been relatively stable since European arrival.
ScoreE - Stable. Population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation
CommentBreeding Bird Survey (BBS) has relatively low credibility in Montana, but shows a decline of 3.8% per year since 1980 which is a 22% decline over a 10 year time period. FWP has harvest data that shows harvested numbers holding steady between 15-40,000 per year since 1979 or so. There are a variety of problems with using hunter reported harvest as a status assessement for populations (e.g., hunter effort is not accounted for), but this probably indicates a relatively stable population over the last 20-30 years.
ScoreG - Slightly threatened. Threats, while recognizable, are of low severity, or affecting only a small portion of the population or area.
CommentLoss of aspen habitats due to climate change. Grazing in some areas.
SeverityLow - Low but nontrivial reduction of species population or reversible degradation or reduction of habitat in area affected, with recovery expected in 10-50 years.
CommentAspen and deciduous shrubs respond quickly to fire or reduced grazing
ScopeLow - 5-20% of total population or area affected
CommentSince species is a habitat generalist, loss of aspen probably does not constitute a very large portion of habitat
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
CommentOngoing but could accelerate
ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).
ScoreC - Moderate. Generalist. Broad-scale or diverse (general) habitat(s) or other abiotic and/or biotic factors are used or required by the species but some key requirements are scarce in the generalized range of the species within the area of interest.
CommentUse a wide variety of habitats, but need understory shrubs or late seral aspen.