ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380531 square kilometers based on Natural Heritage Program range maps that appear on the Montana Field Guide
ScoreD - Moderate Decline (decline of 25-50%)
CommentSpecies was heavily persecuted by early settlers who considered it a threat to domestic foul and sheep. Pesticide application in both breeding and wintering range has also been identified as a cause for declines in last half century.
ScoreF - Increasing. Increase of >10% in population, range, area occupied, and/or number or condition of occurrences
CommentBBS data is of moderate credibility in Montana and shows a significant increase of 2.4% per year or + 27% increase per decade. BBS for surrounding states and provinces mostly show increasing trends. Raptor survey route data in Montana for the past 35 years shows mostly stable, but sometimes widely varying, numbers. Over the last 10 years, raptor survey route data shows a steady and seemingly clearly increasing trend.
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, pesticides on summer and winter ranges and vehicle collisions are probably the greatest threats.
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.
CommentProbably respond relatively quickly to habitat and prey base changes.
ScopeModerate - 20-60% of total population or area affected
CommentGrassland/shrubland habitats being widely (20-605) affected.
ImmediacyModerate - Threat is likely to be operational within 2-5 years.
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.
CommentForage over a large variety of habitats and nest sites aren't that limited.