Spotted eagles are already an endangered species. Now, scientists have discovered that they face yet another danger: war in Ukraine.
Eagles were exposed to conflict during migration through Ukraine, forcing them to deviate from their usual flight path, according to a study published Monday in the journal. Current Biology.
Listed as “vulnerable” by the International Union for Conservation of Nature, spotted eagles have largely been eradicated from Western and Central Europe, according to the study.
However, Polesia, a large marshy region 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 spotted eagles crossed into Ukraine on their usual migration, according to researchers in the United Kingdom and Estonia.
“When the conflict began in February 2022, we were watching things unfold on the news like everyone else, but also sitting there feeling like we knew our birds were about to pass through that area and wondering what that could mean. for them,” the study’s lead author, Charlie Russell, a conservation scientist and ornithologist who is studying for his doctorate at the University of East Anglia in the United Kingdom, told CNN.
Using conflict data and GPS tracking, researchers quantified the impact of the conflict on the migratory behavior of 19 eagles as they passed north through Ukraine to breeding sites in southern Belarus between March and April 2022.
The study authors found that eagles deviated significantly from their usual flight path compared to pre-conflict migrations between 2019 and 2021, with eagles flying further and less directly to breeding sites.
Although the researchers did not have direct observational evidence to determine the stimuli the birds might respond to, they thought the noise and light from military activities might have affected their behavior.
The deviations were greater in areas where the migration route coincided with more military activity, but they differed for each bird due to different exposures and responses to conflict, according to the researchers.
Due to greater diversions, birds had to travel further and their migrations also took longer to complete.
Females, for example, spent an average of 246 hours traveling to breeding sites, rather than the pre-conflict time of about 193 hours, according to the study.
Eagles traveled an average of 85 kilometers (53 miles) further, and in one extreme case, one bird flew 250 kilometers (155 miles) further compared to previous years, Russell said.
The men were found to be traveling more slowly, reaching an average speed of about 7.66 meters (25 feet) per second rather than the pre-conflict average of about 9.75 meters (32 feet) per second.
Researchers observed no differences in migration performance and diversion patterns outside of Ukraine, according to the study.
Potential Reproduction Risk
The other significant discovery was that birds made fewer stops than in previous years.
Stopover sites are essential places for eagles to get food, water, rest and resupply, as well as shelter from bad weather during their long journeys, according to researchers.
While 18 tracked individuals – 90% of tracked eagles – made stops in Ukraine during migration between 2018 and 2021, only six made stops in 2022.
In the years before the conflict, 11 of the eagles used common stopover sites in Ukrainian Polesia, but these sites are unused as of 2022.
“The combination of those two things, having to fly forever and expend more energy, and the reduced ability to recover that energy, is something that we think will have had sublethal fitness costs, which may have been carried over into that year’s breeding season. ,” Russell added.
Reduced fitness and delayed initiation of reproduction due to time spent recovering from travel could reduce reproductive success, which is already relatively low in the population, as well as impact chick supply and the hatch date of young birds, according to with the study.
“I think it is very important to understand the different stresses that the environment is facing as a result of the conflict, so that in a post-conflict scenario we can better support not only spotted eagles but also wider ecosystems to recover. ,” said Russell. he said.
“We know very little about the impacts of human conflict on wildlife, especially when it comes to migratory species, so this study fills an important knowledge gap,” said Professor Nathalie Pettorelli, an applied ecologist and senior researcher at the Zoological Society of London. . she told CNN Tuesday.
Pettorelli, who was not involved in the study, added that understanding what affects eagles’ survival is “key” to ensuring they have a future.
“More generally, human conflicts are increasing globally, underlining the need for more research into the impacts of conflicts on biodiversity and, where possible, the development of effective mitigation policies,” said Pettorelli.
Ukraine accused Russia of “ecocide” after suffering an environmental catastrophe in July due to the collapse of the Kakhovka dam in the south of the country, which caused the deaths of more than 100 people, as well as the destruction of agricultural land and nature reserves.
Russell said the war in Ukraine is “really raising the profile of some of the environmental issues caused by the conflict. And it’s not just in Ukraine. This is something that will happen to different degrees in other conflict zones as well.”
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