Eagles reroute flight paths to avoid Ukraine's conflict zones

Scientists have discovered that migrating eagles, whose migration paths cross Ukraine, have changed their flight routes to avoid areas affected by armed conflict. Data collected from GPS transmitters show that more excellent spotted eagles avoid these areas and limit or forego stopping in Ukraine for rest. Researchers claim that the change in routes extends their return to breeding areas and requires more effort.

The study revealed for the first time how the war affects the migration of the endangered greater spotted eagle species flying over Ukraine. The analysis, initiated before Russia invaded Ukraine in 2022 by a team of scientists from the University of East Anglia (UEA), the British Trust for Ornithology (BTO), and the Estonian University of Life Sciences, unexpectedly included a new, dramatic factor—armed conflict.

Initially, scientists focused on assessing the impact of atmospheric phenomena and land use changes on this species' migration patterns. However, when the invasion began in February 2022, researchers started observing how the war affected these delicate birds. The team monitored their flight paths over Ukraine by using GPS devices installed on 19 greater spotted eagles. The birds encountered war activities along their way—artillery shelling, jet flights, tank movements, and mass movements of civilians and soldiers.

The publication in "Current Biology" describes how the birds had to change their traditional migration route significantly, limiting time spent in Ukrainian resting areas or completely bypassing them. Before the invasion, 90% of eagles stopped in these areas, but after the war began, this number dropped to just 30%. Males moved slower, and the average additional distance the birds had to travel was 85 kilometres, which significantly extended the migration time. This increased migration time for females from about 193 to 246 hours and for males from 125 to 181 hours.

Charlie Russell, the lead author of the UEA study, commented on its findings: The war in Ukraine has had a devastating impact on people and the environment. Our findings provide a rare window into how conflicts affect wildlife, improving our understanding of the potential impacts of exposure to such events or other extreme human activities that are difficult to predict or monitor.

Scientists emphasize that this disruption can significantly affect bird behaviour and their survival adaptation. Among the consequences, they mention delayed reproduction, as the birds will need more time to recover after such extended journeys. This, in turn, can affect the young's chances, as food may be less available when the eggs hatch.