Maps of bird diversity in the USA include the total species richness, endemic species, threatened species, and small-ranged species. Species considered small-ranged are those with a geographic range size smaller than the median (i.e., the 50% of species with the smallest ranges) either globally or of the species in the lower 48 states. Maps are derived from digital distribution maps for all the world’s birds in BirdLife International and NatureServe (2013).
These maps, as well as the conservation priorities map, first appeared in the scientific publication, “U.S. protected lands mismatch biodiversity priorities,” by Clinton N. Jenkins, Kyle S. Van Houtan, Stuart L. Pimm, and Joseph O. Sexton. Published April 6, 2015, in Proceedings of the National Academy of Sciences. www.pnas.org/cgi/doi/10.1073/pnas.1418034112
Maps were generated at a spatial resolution of 10×10 km for rasters, or maintained as vector format where more appropriate, and use an Albers Equal Area Conic projection. Maps represent native, extant species only. Tables of the species included are available for download here.
A zip file with higher resolution jpegs of the above maps can be downloaded here.