Willow Flycatcher (Empidonax traillii) Conservation Status Review
Review Date = 09/15/2008
ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380584 square kilometers based on Natural Heritage Program range maps
Area of Occupancy
ScoreH - >20,000 km squared (greater than 5,000,000 acres)
Comment23662 square kilometers based on GAP predicted model.
ScoreD - Moderate Decline (decline of 25-50%)
CommentDeclining riparian areas and elimination of beaver across large regions has likely resulted in a moderate decline
ScoreE - Stable. Population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation
CommentBreeding Bird Survey (BBS) data is of high quality, 1966-2007 trend is -0.6% per year; BBS 1980-2007 trend is -2.1% per year
ScoreE - Localized substantial threat. Threat is moderate to severe for a small but significant proportion of the population or area.
CommentAltered hydrology through loss of beaver and climate change to a greater extent and grazing to a lesser extent. Also potentially affected by exotic riparian species.
SeverityModerate - Major reduction of species population or long-term degradation or reduction of habitat in Montana, requiring 50-100 years for recovery.
CommentWater demands will hamper recovery of habitats.
ScopeLow - 5-20% of total population or area affected
CommentRiparian areas are threatened across Montana in a slow and continuous manner
ImmediacyHigh - Threat is operational (happening now) or imminent (within a year).
CommentOngoing and accelerating
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).
ScoreB - Narrow. Specialist. Specific habitat(s) or other abiotic and/or biotic factors (see above) are used or required by the Element, but these key requirements are common and within the generalized range of the species within the area of interest.
CommentShrubby riparian specialist.