Grasshopper Sparrow (Ammodramus savannarum) Conservation Status Review
Review Date = 12/20/2011
ScoreH - >1,000,000 individuals
CommentRecent Integrated Monitoring in Bird Conservation Regions (IMBCR) data for 2010 estimates the statewide population at 4,494,627 +/- SD of 988,818.
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380,531 square kilometers based on Natural Heritage Program range maps that appear on the Montana Field Guide.
Area of Occupancy
ScoreU - Unknown
ScoreD - Moderate Decline (decline of 25-50%)
CommentGrassland and lower cover shrubland covertypes have been drastically reduced in Montana 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) data for Montana is of high credibility, but insignificant, and shows a +1.1% increase per year or 12% increase per decade. Most surrounding states and provinces show declines. Given insignificant nature of Montana's trend our short term trend may be most appropriately recognized as stable.
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.
CommentHabitat loss, grazing, and mowing all represent threats to the species.
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.
CommentGrassland cover structure can recover relatively quickly from grazing and fire and the species does use CRP.
ScopeModerate - 20-60% of total population or area affected
CommentOne threat or another is present across large portion (20-60%) of the landscape.
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
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).
CommentNot Intrinsically Vulnerable. Species matures quickly, reproduces frequently, and/or has a high fecundity such that populations recover quickly (< 5 years or 2 generations) from decreases in abundance. Species has good dispersal capabilities such that extirpated populations generally become reestablished through natural recolonization.
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.
CommentModerate generalist. Need moderately tall and dense grassland that can be patchy or continuous.
Raw Conservation Status Score
3.5 + 0.5 (population size) + 0.0 (geographic distribution) + 0.0 (short-term trend) + 0.0 (threats) = 4.0