Nature 444, 93–96 (2006)

165 mammalian species (from a total of 4,269) listed as ‘data deficient’ by the IUCN were inadvertently omitted from the total and rare species richness values presented. In addition, the spatially corrected P values associated with richness correlations presented incorrectly used a one-tailed significance test for positive correlations. Consequently, a number of numerical results in the original paper have changed. Our original conclusions are not affected.

A complete set of revised display items is available for comparison as Supplementary Information to this corrigendum. The range of correlations between total richness values reported in the original paper (0.79 = r = 0.90) are unchanged to 2 decimal places, however that between rare species richness values should be 0.22 = r = 0.47 (originally 0.24 = r = 0.48). The lower quartile of the range size distribution of mammals should be 41,728 km2 (originally 41,685 km2). 19.3% of hotspot cells are common to all three vertebrate classes (originally 17.8%), compared to 2% (originally 2.3%) of rarity hotspots. The median range sizes we reported for illustrative purposes in the Methods section are derived from distribution maps on the analytical grid, not from polygonal areas of occupancy.

We thank Natalie Cooper for discovering the error in the significance testing.