Background/Question/Methods
Understanding species extinction risk is crucial for effective biodiversity conservation. Recent studies highlight the significance of intrinsic traits (e.g., body size) or extrinsic factors (e.g., human density) or both, as well as geographic range size, in predicting IUCN Red List threat status for vertebrates. Here, by using species-based generalized linear mixed-modeling, we examine a suite of relevant correlates, ranging from life-history, ecology to environmental predictors, of extinction risk for approximately 4000 (the largest dataset to date) living terrestrial bird species.
Results/Conclusions
We show that species with high past range loss (defined as the proportion of current range size transformed by past human encroachment) are more likely to be listed as threatened than those with low range loss. By itself, geographic range size decreases with increasing threat status, emerging as the most important correlate (20% of deviance explained) of IUCN threat status. Combined, increasing body mass, past range loss, and human population density, and decreasing range size and elevational range increase bird extinction risk (28% of deviance explained). However, shared ancestry has minimal effect on the results. We discuss reasons for the unaccountability of the residual deviance. Overall, our findings advance the field of predictive conservation science under a more rigorous conceptual and statistical framework.