Abstract/Summary

Background: Climate change due to anthropogenic global warming is the most important factor that will afect future range distribution of species and will shape future biogeographic patterns. While much efort has been expended in understanding how climate change will afect rare and declining species we have less of an understanding of the likely consequences for some abundant species. The Common Grackle (Quiscalus quiscula; Linnaeus 1758), though declining in portions of its range, is a widespread blackbird (Icteridae) species in North America east of the Rocky Mountains. This study examined how climate change might afect the future range distribution of Common Grackles. Methods: We used the R package Wallace and six general climate models (ACCESS1-0, BCC-CSM1-1, CESM1-CAM5- 1-FV2, CNRM-CM5, MIROC-ESM, and MPI-ESM-LR) available for the future (2070) to identify climatically suitable areas, with an ecological niche modelling approach that includes the use of environmental conditions. Results: Future projections suggested a signifcant expansion from the current range into northern parts of North America and Alaska, even under more optimistic climate change scenarios. Additionally, there is evidence of possible future colonization of islands in the Caribbean as well as coastal regions in eastern Central America. The most important bioclimatic variables for model predictions were Annual Mean Temperature, Temperature Seasonality, Mean Temperature of Wettest Quarter and Annual Precipitation. Conclusions: The results suggest that the Common Grackle could continue to expand its range in North America over the next 50 years. This research is important in helping us understand how climate change will afect future range patterns of widespread, common bird species.