Advances in tracking technology during the last decade have shown that migratory birds have the capacity to fly longer and faster than we previously thought was possible. Yet, we do not know how birds perform these seemingly impossible travels as it previously only was possible to record spatiotemporal patterns. A new tracking technology now allow us to record key aspects of migratory behaviour and physiology of birds throughout their migration. With this new technology, we learn not only where birds go, but also how they get there. This gives us the possibility to in detail study complete journeys and strategies, allowing us to change our understanding of how birds succeed with their seemingly impossible migratory journeys.
The overall aim of this project is to reveal constraints and the behavioural and physiological adaptations that has evolved to overcome them, thus making the extreme performances of migratory birds possible. This goal will be met by using novel tracking devices, multisensor data loggers, that in addition to spatiotemporal patterns also record behaviour, including flight altitudes, temperature and detailed timing of flights and stopovers during the entire migration cycle. The few multisensor tracking studies carried out to date have provided hints of stunning new insights, and seriously challenged previously assumed limits on peak flight altitudes, in-flight changes of altitudes, and duration of individual flights. In particular, the PI has together with colleagues previously discovered a totally unexpected altitudinal behaviour: some bird species change their flight altitude between night and day, and fly at extremely high altitudes during the day (up to 6000-8000 m). But what makes a migratory bird fly as high as Mount Everest, even when there are no mountains to cross?
By a multisensor data logging programme, combined with wind tunnel experiments and field studies, the proposed project will change our understanding of the possibilities and limitations of bird migration. This will be done by disentangling the causes and consequences of bird’s altitudinal behaviour, the flexibility, timing and duration of migratory flights, and the costs and consequences of these behaviours.
This is first and foremost a leading-edge project in basic research. Yet, migration is an important part of the life cycle of many organisms, not least birds, and for humans one of the most fascinating events in nature. Today, many long-distance migratory birds are declining and a better understanding of animal migration in general is necessary to predict how global change may affect migratory species.
