Mapping busy bird migration airspace together with the Air Force and the KNMI

For more than twenty years, University of Amsterdam researchers have been working with the Royal Netherlands Air Force and the Royal Netherlands Meteorological Institute (KNMI) to measure and forecast bird migration in the airspace, with a view to aviation safety and nature conservation. The radar studies deliver not only practical benefits but also new insights into bird behaviour.

The Netherlands is a special area when it comes to bird migration. Several European flyways converge here, resulting in concentrated activity in the air. Birds migrate over parts of the Netherlands further into Europe, through areas where airplanes are constantly taking off and landing and wind turbines reach up to 200 meters high.

In this busy airspace, a special collaboration has emerged. For more than twenty years, scientists from the UvA have been working together with the Royal Netherlands Air Force and the KNMI to measure and predict bird migration in the airspace. Initially, they had one clear goal: to reduce the risk of collisions between birds and fighter jets.

“Collisions with birds can cause major damage to aircraft and pose a risk to both pilots and birds,” says Professor Judy Shamoun Baranes. “Fighter jets fly at high speed and often at low altitude, exactly where many birds are. There is hardly any time to swerve.”

FlySafe: weather radar as a safety system

To reduce the risk, the Air Force uses FlySafe, a system that maps and predicts bird migration. FlySafe is operated operationally by the KNMI and uses weather radars in the Netherlands, Belgium and Germany.

These radar systems were designed for weather observations and short‑term forecasts, but they also detect birds. UvA researchers developed models that link observations of bird migration from radar data to weather conditions. Shamoun-Baranes: “In this way you can predict when large-scale bird migration will start and at what altitude the birds will be flying. The Air Force can then move training flights to times when there are fewer birds in the air.”

FlySafe has now been running for almost fifteen years and was recently modernized with better algorithms and interactive maps. Via the KNMI Data Platform, the bird profiles and migration maps are also publicly available for research and other applications.

New knowledge about bird migration

The radar studies not only yield practical benefits, but also new insights into bird behavior. “We see that bird migration is not an even ‘blanket’ over Europe. There are busy routes and quieter areas, and the patterns along the coast differ from those inland,” says researcher Bart Kranstauber.

With radars, researchers can also measure throughout the night, across large areas and for all species at once – something that is hardly possible with transmitters or visual observations. “We can use that knowledge when planning wind turbines on land and in the North Sea, in order to avoid the busiest migration corridors as much as possible. And we contribute to models that ensure offshore wind turbines are shut down efficiently whenever major bird migration is expected.”

Unique Dutch collaboration, European ambitions

The long-term collaboration between the UvA, the Air Force and the KNMI is special, according to Shamoun Baranes: “The Air Force invests in advanced radars, the KNMI in open data and visualization, and we in ecological knowledge and models. Together we can go much further than each of us could alone.”

The ambition extends beyond the Netherlands. Researchers are working on predictive models at the European scale, so that in time bird migration will become just as visible and predictable as the weather. “Birds migrate across borders,” says Shamoun Baranes. “A European bird migration ‘weather report’ would be a huge step forward for flight safety, nature conservation and the energy transition.”

Text en image: Institute for Biodiversity and Ecosystem Dynamics (leadfoto: ducks migrating at sunset)