Understanding changes in bird populations – the role of bird marking

Abstract

Studies of marked birds play a central role in research on avian population dynamics and life histories because they are the main means of estimating survival, recruitment and dispersal. Integrated Population Monitoring aims to combine such information from ringing with data on abundance, productivity and the environment in order to develop population models that address applied questions. Diagnosing the demographic and environmental causes of population declines provides a basis for developing management prescriptions for population recovery. We discuss examples of how such studies are contributing to the conservation of European farmland birds and to understanding declines in Afro–Palaearctic migrants. Adaptive harvest management of North American duck populations demonstrates that similar principles apply to the management of quarry species. Over the next two decades we expect significant advances in our understanding of seasonal variation in demographic rates, of density dependence and of the ways in which continental‐scale population dynamics are built up from processes operating at much smaller spatial scales. This will be achieved through analyses of large‐scale data sets, the combination of conventional and new technologies and the widespread application of fully integrated modelling methods. Large‐scale data gathering through national ringing centres will play a key part in this process.