Maps of bird diversity include the total species richness (using breeding, non-breeding, and combined ranges), major taxonomic groups (non-Passeriformes, Passeriformes, Tyranni, Passeri), threatened species, and small-ranged species. Species considered small-ranged are those with a geographic range size smaller than the global median (i.e., the 50% of species with the smallest ranges). Maps are based on data from BirdLife International, 2011 version.
For birds, current maps for small-ranged species and threatened species have been generated at a spatial resolution of 10x10km. Maps for major taxonomic groups of birds and total richness have been generated at a spatial resolution of 50x50km. Maps represent native, extant species only. Tables of the bird species included are available for download (http://biodiversitymapping.org/birds.htm).