White-tailed eagles are gathering near residential areas in groups of 10-15 individuals in the region of Vaasa in western Finland, locals and the World Wildlife Fund (WWF) report.
WWF environmentalist Pekka Peura told Yle that the unusual gatherings are due to a growing eagle population and crowded habitats.
White-tailed eagles nest in sturdy trees that grow in old forests, and Peura said both are becoming scarce in Vaasa.
The spike in sightings also coincides with the species' migration period and the nesting season, which tends to run from February to April.
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"The window for nesting is pretty wide. Some older white-tailed eagle couples tend to get to business quite early," Peura noted.
Local birdwatchers said they are delighted by the presence of the impressive creatures. A group of eagles is sometimes known as a convocation.
The area known as Kvarken near Vaasa in the Gulf of Bothnia is an important region for white-tailed eagles. In 2017 ornithologists counted 96 hatchlings. Despite a drop to some 70 chicks the following year, researchers say the figures are encouragingly high.
"Considering the fact that there were no sightings whatsoever in the 1970s, and that we haven't located every nest, 70 eagle chicks is a prodigious number," Peura said.
WWF volunteers such as Peura monitor the species' nesting each year and check for possible new sites. New hatchlings are ringed to help track the population.
"The way we do it is that we check the nests we already know of, and if we find new ones or get tips we investigate those, too. And we tag as many young birds as we can when they reach the right age."
Edit: Vaasa and Kvarken are located in western Finland.