Field Sparrow (Spizella pusilla) Conservation Status Review
Review Date = 12/22/2011
Population Size
ScoreF - 10,000-100,000 individuals
CommentRecent Integrated Monitoring in Bird Conservation Regions (IMBCR) data for 2010 estimates the statewide population at 78,748 +/- SD of 22,049.
Range Extent
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment240,762 square kilometers based on Natural Heritage Program range maps that appear on the Montana Field Guide
Area of Occupancy
ScoreU - Unknown
CommentUnknown.
Long-term Trend
ScoreE - Relatively Stable (±25% change)
CommentShrubby habitats and areas with scattered woody vegetation have probably been stable (+/- 25%) or have increased since European arrival. The CRP program has likely benifited this species.
Short-term Trend
ScoreE - Stable. Population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation
CommentBBS has moderate credibility in Montana and shows an insignificant increase of +1.4% increase per year or 15% increase per decade. North Dakota has insignificant positive trends. South Dakota has insignificant negative trends. Probably best regarded as stable to within +/- 10% within past 10 years.
Threats
ScoreG - Slightly threatened. Threats, while recognizable, are of low severity, or affecting only a small portion of the population or area.
CommentNo operational threats identified for Montana.
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.
CommentNo operational threats identified for Montana.
ScopeLow - 5-20% of total population or area affected
CommentNo operational threats identified for Montana.
ImmediacyLow - Threat is likely to be operational within 5-20 years.
CommentNo operational threats identified for Montana.
Intrinsic Vulnerability
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.
Environmental Specificity
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. Uses a variety of shrubby habitats, often in or near a variety of riparian types or areas with more mesic vegetation.