Composition of ‘fast–slow’ traits drives avian community stability over North America

Rapid biodiversity loss has triggered decades of research on the relationships between and community stability. Recent studies highlighted importance species traits for understanding biodiversity–stability relationships. The with high growth rates (‘fast’ species) are expected to be less resistant environmental stress but recover faster if disturbed; in contrast, slow (‘slow’ can more slowly disturbed. Such a ‘fast–slow’ trait continuum provides new perspective stability, its validity mainly been examined plant communities. Here, we investigate how composition, together richness factors, regulate avian stability at continental scale. We used bird population records from North American Breeding Bird Survey during 1988–2017 defined as temporal invariability total biomass. calculated community–weighted mean (CWM) functional diversity (FD) four key life-history traits, including body size, nestling period (i.e. egg incubation young fledging), life span clutch size annual number eggs). Environmental factors included temperature, precipitation leaf area index (LAI). Our analyses showed that was driven by CWM trait. Communities dominated ‘fast’ small short large size) were stable than those ‘slow’ long size). Species FD explained much smaller proportions variation Temperature had direct positive effects while affected indirectly influencing composition. study demonstrates composition is major biotic driver over America. most important abiotic factor, effect weaker An integrated framework combining temperature needed understand response communities changing environment. A free Plain Language Summary found within Supporting Information this article.