IUCN richness maps
We developed a range of maps of richness using different techniques outlined here. Firstly, as a comparator we mapped richness using IUCN polygons as well as trimming the IUCN polygons as advocated by Brooks et al 2019. To map richness of African bats based on the IUCN (though this does not include all known species) we downloaded as all Chiroptera from the African continent from the IUCN website (on June 3rd). Firstly we clipped the polygons for a rectangular area over the African continent, then dissolved each species polygon to give a single polygon for each species. We used the “count overlapping polygons” toolbox, split the polygon. To do this we split the polygon into groups of 30 species (the tool works better on lower numbers), numbered outputs sequentially, then converted to rasters (with a resolution of 0.008 degrees, approximately 1km at the equator) then used the raster calculator to add all results to map richness according to the IUCN.