Global Species Richness and Rarity

Species Richness

The maps show species richness patterns for a range of 'species group' – 'region' combinations for which data in Map of Life is data supports this calculation. For data sources, see Expert range maps in MOL Datasets page. The spatial resolution (pixel size) is the finest that is scientifically sound for this data type (see Hurlbert & Jetz, PNAS 2007) – higher resolutions would overestimate actual richness values.

Check back as we are adding more species groups and regions and in the future higher-resolution patterns based on model-driven range predictions.

Species Rarity

"Total range-size rarity" (also called "rarity score", "endemism richness", or "weighted endemism"). Total range-size rarity is given as the count of species present in a region, weighted by their respective range proportion inside the region. Also described as: "Weighted endemism in a cell is the proportion of the distribution of a species that is found in a cell (summed across all species)" (this from our paper Pollock et al 2017, Nature). Note that species rarity is sometimes referred to as species endemism.

"Average range-size rarity", also called "range size rarity" or "species rarity", is simply that value divided by the number of species in a cell: