Western Flycatcher (Empidonax difficilis) 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)
Comment287464 square kilometers based on Natural Heritage Program range maps
Area of Occupancy
ScoreH - >20,000 km squared (greater than 5,000,000 acres)
Comment27,602 square kilometers based on GAP predicted model.
ScoreE - Relatively Stable (±25% change)
CommentRiparian and Douglas Fir forests relatively stable since European arrival.
ScoreU - Unknown. Short-term trend in population, range, area occupied, and number and condition of occurrences unknown.
CommentBreeding Bird Survey (BBS) has low credibility in Montana, but shows a decrease since 1980 of 7.5% per year which is a 54 percent decline over a 10 year time period. Surrounding states have both increasing and decreasing trends. Short term trend may best be regarded as unknown right now.
ScoreF - Widespread, low-severity threat. Threat is of low severity but affects (or would affect) most or a significant portion of the population or area.
CommentLoss of mature forests with cavities and root wads due to fire and beetle kill
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.
CommentNot as restricted to mature forest
ScopeModerate - 20-60% of total population or area affected
CommentFire and beetle kill are drastically changing a large portion of the landscape
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
CommentOngoing but could accelerate
ScoreC - Not Intrinsically Vulnerable. Species matures quickly, reproduces frequently, and/or has high fecundity such that populations recover quickly (< 5 years or 2 generations) from decreases in abundance; or species has high dispersal capability such that extirpated populations soon 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.
CommentRely on mature forests and riparian areas, but not exclusively