CONCLUSION
Based on a global-scale synthesis of avian survival rates, we find evidence that survival increases with decreasing latitude, but that this phenomenon is more nuanced than previous descriptions have characterized. Specifically, we demonstrate that the latitudinal survival gradient is stronger in northern hemisphere species, where climate seasonality may be greater. By including aspects of species life history traits in our models, we could explain a greater portion of the variation in survival rates than with latitude alone. These results indicate the importance of considering an organism’s intrinsic traits as well as the extrinsic factors of their environment when describing broad-scale macroecological patterns. Where peaks in survival occur, how they relate to climatic variables, and how these patterns are likely to change through time and space given the effects of climate change, are of major importance for conservation. We hope that in assembling this database and dissecting some of the global patterns in survival across avian groups and hemispheres, we can provide a platform for future work to target underrepresented regions and taxa and also make a clear path forward to better understanding variation in survival rates, and how it intersects with other life history traits across the world’s avifauna.