The use of ecological traits in extinction risk assessments: A case study on geometrid moths

Identifying ecological traits that make some species more vulnerable than others is vital for predictive conservation science. By identifying these predisposing traits we can predict which species are most prone to decline and gain an understanding of the reasons behind the decline. The aim of this study was to determine the ecological traits that best predict extinction risk and distribution change in Finnish geometrid moths and to develop an understanding of the biological connections between these traits and threats. We found that larval specificity, overwintering stage and flight period length predicted distribution change and extinction risk. There was also an interaction effect between larval specificity and body size on both distribution change and extinction risk. In monophagous species the host plant distribution predicted extinction risk. Even though ecological traits are known to be important determinants of extinction risk, the IUCN red list categorization system is exclusively based on quantitative measures of populations and ignores the ecological traits. Here, we propose that taxon specific ecological data should also be used to predict extinction risk at least on a regional scale to improve the accuracy of the IUCN extinction risk classification.