ScoreU - Unknown
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380530 square kilometers based on Natural Heritage Program range maps
Area of Occupancy
ScoreG - 2,000-20,000 km squared (500,000-5,000,000 acres)
Comment2033 square kilometers based on GAP predicted model.
ScoreE - Relatively Stable (±25% change)
CommentUse reservoirs fairly widely so probably relatively stable compared to pre European times.
ScoreE - Stable. Population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation
CommentBreeding Bird Survey (BBS) data 1966-2007 trend is -1.5% per year; BBS 1980-2007 trend is -1.9% per year
ScoreG - Slightly threatened. Threats, while recognizable, are of low severity, or affecting only a small portion of the population or area.
CommentWetland loss. Climate Change, Contaminants
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.
CommentSpecies use modified habitats as long as it is of a preferred structure.
ScopeLow - 5-20% of total population or area affected
CommentCan use natural wetlands or reservoirs in drainages
ImmediacyHigh - Threat is operational (happening now) or imminent (within a year).
CommentOngoing and climate change could increase threat
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.
CommentCan use a wide variety of wetlands.