Global patterns and environmental correlates of high-priority conservation areas for vertebrates

Aim: A major challenge for the emerging discipline of conservation biogeography is to identify conservation areas and understand the factors and processes that govern the spatial distribution of those areas. We aimed to identify high-priority conservation cells (HPCC) - 1° cells that efficiently represent species - for amphibians, birds and mammals at the global extent, to identify the environmental variables associated with conservation priority, and to evaluate how well the areas of highest species richness correspond to these high-priority areas. Location: A global analysis. Methods: Distribution maps for 21,697 vertebrates and complementarity-based approaches were used to map HPCCs for vertebrates. We used 41 potential predictor variables and varimax-rotated factor analysis (VrFA) to identify sets of relatively uncorrelated environmental factors, and then used random forest models to investigate the relationships between VrFA factors and vertebrate conservation priorities. Finally, we evaluated whether species richness and threatened-species richness were efficient surrogates to identify HPCCs for each vertebrate taxon. Results: For each of the three taxa, HPCCs were concentrated in the Neotropical, Afrotropical and Indo-Malay biogeographical realms. The spatial distribution of HPCCs was strongly correlated with environmental variables, especially energy-related variables. The cells with the highest species richness did not correspond to HPCCs for either birds or mammals. Discussion: We suggest that elucidating the patterns and drivers of conservation priority could become a major focus of conservation biogeography. The ability to identify high-priority conservation sites from the environmental conditions in those sites may improve how sites are prioritized for conservation, so that all or most species can be conserved in affordable areas.