Terrestrial Rare Bird Richness - ACE [ds2711]

Rare Bird Richness, Areas of Conservation Emphasis (ACE), version 3.0.

Rare species richness is a measure of the diversity of rare species in the landscape, and is one measurement used to describe the distribution of overall species biodiversity in California for the California Department of Fish and Wildlife’s (CDFW) Areas of Conservation Emphasis Project (ACE). Other measures of terrestrial species biodiversity included in the ACE terrestrial biodiversity summary are native species richness and terrestrial endemism. Here, rare species richness represents a count of the total number of rare terrestrial species potentially present in each hexagon based on documented species occurrence information. The data can be used to view patterns of species rarity, and to identify areas of high rarity richness across the state and in each ecoregion. Users can view a list of species that contribute to the richness counts for each hexagon.

The rare species richness summary depicts relative rare species diversity within each ecoregion across the state, so that areas of highest diversity within each ecoregion are highlighted. To achieve this, the data in the summary layer was normalized by taxonomic group and by ecoregion (see Data Sources and Models Used, below). The rare species richness by taxonomic group layers give a statewide overview of rarity for each individual taxonomic group, showing counts of species per hexagon for amphibians, birds, mammals, plants, and reptiles.