For birds, flying takes a lot of energy. Therefore, it is extremely important that they use the energy as efficiently as possible. When, for example, the bar-tailed godwit makes its non-stop one-week flight of 11,000 kilometres from Alaska to New Zealand, it is a test of strength which, according to Anders Hedenström, corresponds to if a person were to run 1,200 marathons in a row. Without stopping and without eating.

To understand how birds are able to do this, the researchers will study aerodynamics, the movement of the wings, how efficiently they convert energy into transport, and whether the route is optimal or not. New microdata loggers have been developed that register acceleration, air pressure and position. The researchers will also develop unique data loggers that will register the activity in the air and what it costs the birds to move, for example, the energy expended.

“With this tool, we will also be able to identify factors that explain why many migratory birds have decreased in number, both in Europe and in North America. We also aim to be able to predict migration pattern variations due to climate change”, concludes Anders Hedenström.