Data from: Correlates of extinction risk in squamate reptiles: the relative importance of biology, geography, threat and range size

Aim Evaluating the relative roles of biological traits and environmental
factors that predispose species to an elevated risk of extinction is of
fundamental importance to macroecology. Identifying species that possess
extinction-promoting traits allows targeted conservation action before
precipitous declines occur. Such analyses have been carried out for
several vertebrate groups, with the notable exception of reptiles. We
identify traits correlating with high extinction risk in squamate
reptiles, assess whether these differ with geography, taxonomy and
threats, and make recommendations for future Red List assessments.
Location Global. Methods We collected data on biological traits and
environmental factors for a representative sample of 1139 species of
squamate reptiles. We used phylogenetically controlled regression models
to identify general correlates of extinction risk, threat-specific
correlates of risk and realm-specific correlates of risk. We also assessed
the relative importance of range size versus other factors through
multiplicative bivariate models, partial regressions and variance
partitioning. Results Range size was the most important predictor of
extinction risk, reflecting the high frequency of reptiles assessed under
range-based IUCN criteria. Habitat specialists occupying accessible ranges
were at a greater risk of extinction: although these factors never
contributed more than 10% to the variance in extinction risk, they showed
significant interactions with range size. The predictive power of our
global models ranged from 23% to 29%. The general overall pattern remained
the same among geographical, taxonomic and threat-specific data subsets.
Main conclusions Proactive conservation requires shortcuts to identify
species at high risk of extinction. Regardless of location, squamate
reptiles that are range-restricted habitat specialists living in areas
highly accessible to humans are likely to become extinct first.
Prioritizing species that exhibit such traits could forestall extinction.
Integration of data sources on human pressures, such as accessibility of
species ranges, may aid robust and time-efficient assessments of species
extinction risk.