Greater spotted eagles, already a threatened species, are now facing a new danger: the war in Ukraine. According to a study published Monday in the journal Current Biology, these eagles have been exposed to conflict events while migrating through Ukraine, forcing them to deviate from their usual flight paths.
Impact of Conflict on Eagles
Listed as “vulnerable” by the International Union for Conservation of Nature, greater spotted eagles have been largely eradicated from western and central Europe. However, the Polesia region—a large wetland area bordering Poland, Belarus, Ukraine, and Russia—remains a stronghold for the species.
On March 1, 2022, a week after Russia invaded Ukraine, the first of 21 tagged greater spotted eagles crossed into Ukraine on its usual migration route, reported researchers from the UK and Estonia.
“When the conflict started in February 2022, we were watching things unfold on the news like everyone else, but we also knew our birds were about to pass through that area,” said Charlie Russell, the lead study author and a conservation scientist and ornithologist pursuing his PhD at the University of East Anglia in the UK, to CNN.
Deviations in Migration
Using conflict data and GPS tracking, researchers quantified the impact of the conflict on the migratory behavior of 19 eagles heading north to breeding grounds in southern Belarus between March and April 2022. The study found that the eagles significantly diverted from their usual flight paths compared to pre-conflict migrations from 2019 to 2021. These birds flew further and less directly to their breeding grounds.
While researchers did not have direct observational evidence of what stimuli the birds responded to, they speculated that noise and light from military activities could have affected their behavior. The deviations were more pronounced in areas with increased military activity.
Increased Travel Distance and Time
The eagles had to travel further and took longer to complete their migrations. For example, females spent an average of 246 hours traveling to breeding grounds, compared to 193 hours before the conflict. On average, the eagles traveled 85 kilometers (53 miles) further, with one bird flying an additional 250 kilometers (155 miles) compared to previous years. Males traveled more slowly, averaging 7.66 meters (25 feet) per second instead of the pre-conflict average of 9.75 meters (32 feet) per second.
Decreased Stopovers
Another significant finding was the reduction in stopovers, which are crucial for eagles to rest, refuel, and find shelter during their long journeys. Before the conflict, 90% of tracked eagles made stopovers in Ukraine, but in 2022, only six did. Common stopover sites in Ukrainian Polesia, used by 11 eagles between 2018 and 2021, were not used at all in 2022.
Potential Breeding Risks
The combination of increased travel distance and decreased stopovers likely had sublethal fitness costs, potentially affecting the eagles’ breeding success. Reduced fitness and delayed breeding onset could lower breeding success, already relatively low in this population, and impact chick provisioning and fledgling dates.
Understanding Conflict’s Impact on Wildlife
Russell emphasized the importance of understanding the environmental stresses caused by conflict to better support wildlife recovery post-conflict. Professor Nathalie Pettorelli, an applied ecologist and senior research fellow at the Zoological Society of London, noted that understanding the impacts of human conflicts on wildlife, particularly migratory species, is crucial for ensuring their future survival.