This Web site provides a search facility for quickly locating and downloading 1-kilometer (30 arc-second) resolution grids of the distribution of species. Data are available for global amphibian distributions, and for birds and mammals in the Americas. Clicking on the advanced tab to your left will provide you with access to individual species distribution grids, along with family grids that show the density and distribution of species within a given family. The grids are available in .BIL format and are distributed in two forms: "original grids" that include grid values designating the status of occurrence (e.g., 1 = extant, 2 = possibly present, 3 = probably extinct, etc.), and "presence grids" that represent the "extant" category of the original grids as a grid value of "1," and all other areas as "0". (see methods)
Shapefiles are available for download courtesy of Natureserve. The grids are intended to be of assistance to researchers for modeling, conservation, and human dimensions research purposes.
Users can convert the .BIL images to GRIDs using ArcInfo workstation IMAGEGRID command by using ArcGIS Desktop raster conversion tools in either ArcMap or ArcCatalog. Syntax for IMAGEGRID command in ArcInfo is as follows:
Arc: IMAGEGRID <Image.BIL file> <Out_grid>