ESR 3:31-42 (2007)  -  doi:10.3354/esr003031

ABSTRACT: Endemic taxa are those restricted to a specific area, and can be defined as the exclusive biodiversity of a region. Areas with high endemic numbers are irreplaceable, and are of high priority for conservation. We investigated global patterns of endemicity of terrestrial vertebrates (mammals, birds, reptiles and amphibians) by employing data from World Wildlife Fund-US on 26452 species distributions (endemic and non-endemic) within 796 ecoregions. Ecoregions represent global ecosystem and habitat types at a landscape level. We explored the entire dataset by first using a principal components analysis, PCA, to identify which parameters and ordinations (transformations) best characterise the ecoregions. PCA identified the empirical logit transformation of proportional endemicity, not absolute or relative endemicity, as the appropriate variable. We prioritised ecoregions by ranking the empirical logit transformation of proportional endemicity, standardised across animal groups to avoid taxonomic biases. Finally, we analysed how ecoregion characteristics and the degree of isolation correlated with endemicity in all studied groups, by fitting logistic regression models. We argue that using our method, conservationists can better denote areas of importance for protection of endemic biodiversity worldwide.

KEY WORDS: Endemic species · Species richness · Terrestrial vertebrates · Ecoregions · Prioritisation · Isolation