OdonTraits Europe. A comprehensive traits dataset for European dragonflies and damselflies.

Species traits are an important facet of biodiversity and are useful for testing many ecological and evolutionary hypotheses. Many initiatives to centralize species traits have emerged in recent years, but there are still large gaps in species traits' knowledge in the literature. Odonata (dragonflies and damselflies) are present in most freshwater and surrounding ecosystems and are important indicators of freshwater health and conditions across the land-water interface. They are also important predators and prey both as larvae and adults and are vital to land-water energy transfers and community functioning. Here we present OdonTraits Europe, a database aggregating traits of all 143 European resident Odonata species. Our database compiles 43 traits representing adult and larvae morphology, life history, behaviour, phenology, and other ecological attributes, along with species legal, endemism, and conservation status, with a taxonomic coverage of >95% for all traits. Accessible and robust coverage of Odonata species traits will help to advance knowledge and applications involving this sentinel of the freshwater realm.