Chestnut-collared Longspur (Calcarius ornatus) Conservation Status Review
Review Date = 12/20/2011
ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment254,055 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 habitats have been heavily impacted since European arrival and species has probably declined by 25-50% over this time period.
ScoreD - Declining. Decline of 10-30% in population, range, area occupied, and/or number or condition of occurrences
CommentBreeding Bird Survey (BBS) data for Montana is of high credibility and shows a -3.3% decline per year or 29% decline per decade. Declines for virtually all surrounding states and provinces. Trends on North Valley County Point Counts between 2001 and 2008 showed a 1% per year increase in the percent of points the species was detected on and a 4% per year increase in the number of birds. Due to declining trends in all surrounding areas and Montana's large percentage of the global breeding population this is probably best recognized as a class D of decline.
ScoreB - Moderate and imminent threat. Threat is moderate to severe and imminent for a significant proportion (20-60%) of the population or area.
CommentLoss of native prairie is the greatest threat to the species, but altered grazing and fire regimes also represent threats. Breeding densities in grazed pastures are 9 times higher than in ungrazed pastures. Densities were higher in cropland than in adjacent tall dense idle CRP lands in North Dakota. Natural frequency, intensity, and spatial distribution of fire and grazing would probably promote species conservation.
SeverityModerate - Major reduction of species population or long-term degradation or reduction of habitat in Montana, requiring 50-100 years for recovery.
CommentSpecies seems capable of responding quickly to restored disturbances, but sod busting seems to be a long term challenge for recovery.
ScopeModerate - 20-60% of total population or area affected
CommentUncertain if 20% of grassland habitats would be lost in next 15 years, but species experts agree that the species faces threats across large portion of range.
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.
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.
CommentNarrow Specialist. Dependent on shortgrass prairie (grass height less than 12 inches with less than 8 inches probably ideal for nesting). This species is found to prefer double the density of grass that McCown's Longspur did at North Valley County monitoring points.
Raw Conservation Status Score
3.5 + 0.0 (geographic distribution) + 0.0 (environmental specificity) - 0.25 (short-term trend) - 0.75 (threats) = 2.5, but negative trends indicate that rounding to S2 is more justifiable than S3.