The mysteries of bird migration - still much to be learnt

摘要

Bird ringing has unveiled many mysteries of avian migrations, notably routes and destinations. However, there is still much to be explored by the use of ringing and other marking techniques. Satellite tracking, geolocation and global positioning systems are new tools, as well as particular chemical and molecular markers which appear to be very useful in the study of bird migration by delineating origin of birds and connectivity between breeding and non-breeding grounds. Understanding of bird migrations also gained much from captive studies about the internal mechanisms in the control of bird migration, but we still lack knowledge about external factors, such as food availability, weather, competitors, parasites or diseases. This paper summarises ongoing studies on Northern Wheatears Oenanthe oenanthe to illustrate the benefit of such an integrated approach. Future migration research must aim much more at comparative research and a more integrated approach at various spatial and temporal scales, and linking various sub-disciplines. It is also important to realise that migration is only one part of the life-cycle of a migrating species. Thus, linking migration and breeding is another future challenge, for both basic science and conservation of migratory birds.