Potential effects of climate change on the distribution of waterbirds in the Prairie Pothole Region, U.S.A.
Wetland-dependent birds are considered to be at particularly high risk for negative climate change effects. Current and future distributions of American Bittern ( Botaurus lentiginosus ), American Coot ( Fulica americana ), Black Tern ( Chlidonias niger ), Pied-billed Grebe ( Podilymbus podiceps ) and Sora ( Porzana carolina ), five waterbird species common in the Prairie Pothole Region (PPR), were predicted using species distribution models (SDMs) in combination with climate data that projected a drier future for the PPR. Regional-scale SDMs were created for the U.S. PPR using breeding bird survey occurrence records for 1971-2000 and wetland and climate parameters. For each waterbird species, current distribution and four potential future distributions were predicted: all combinations of two Global Circulation Models and two emissions scenarios. Averaged for all five species, the ensemble range reduction was 64%. However, projected range losses for individual species varied widely with Sora and Black Tern projected to lose close to 100% and American Bittern 29% of their current range. Future distributions were also projected to a hypothetical landscape where wetlands were numerous and constant to highlight areas suitable as conservation reserves under a drier future climate. The ensemble model indicated that northeastern North Dakota and northern Minnesota would be the best areas for conservation reserves within the U.S. PPR under the modeled conditions.