{"id":433,"date":"2026-09-07T16:39:58","date_gmt":"2026-09-07T14:39:58","guid":{"rendered":"https:\/\/sparrow.up.poznan.pl\/life\/en\/?p=433"},"modified":"2026-09-07T16:39:58","modified_gmt":"2026-09-07T14:39:58","slug":"results-of-breeding-monitoring-of-the-greater-spotted-eagle-in-western-polesie-in-2025","status":"publish","type":"post","link":"https:\/\/sparrow.up.poznan.pl\/life\/en\/2026\/09\/07\/results-of-breeding-monitoring-of-the-greater-spotted-eagle-in-western-polesie-in-2025\/","title":{"rendered":"Results of breeding monitoring of the Greater Spotted Eagle in Western Polesie in 2025"},"content":{"rendered":"\n<p>Currently, the core breeding population of the Greater Spotted Eagle (<em>Clanga clanga<\/em>) in Ukraine is concentrated in the Rivne Nature Reserve, where annual surveys are conducted to monitor various aspects of breeding biology. These surveys began in 2012, as reported in articles published on the website of the <a href=\"https:\/\/raptors.org.ua\/tag\/birds-of-prey-rivne-reserve\">Ukrainian Center for the Study of Birds of Prey<\/a>. Another article published on <a href=\"https:\/\/raptors.org.ua\/7509\">this website<\/a> by M. Franchuk and A. Simon summarizes data from the Greater Spotted Eagle monitoring in Western Polesie, Ukraine, in 2025.<\/p>\n\n\n\n<p>The surveys traditionally cover the Rivne Nature Reserve and the Pripyat-Stokhod National Park. In addition to traditional research, monitoring of the Greater Spotted Eagle&#8217;s breeding status continued using camera traps (this research began in 2019), which were installed on nests in July 2025. The main goal of the research is to determine the breeding success and specific breeding biology of each pair. In total, camera traps were installed on seven Greater Spotted Eagle nests (six in the Rivne Nature Reserve and one in the Pripyat-Stokhod National Park). Such research was first conducted in the Pripyat-Stokhod National Park. The camera traps are set to the following operating mode: three photos taken three minutes apart, provided there is activity in the nest; the image size is 5 MB. In addition to the camera trap, backup power supplies and high-capacity (125 GB) memory cards were installed. This research method is very informative because it allows for the observation of various aspects of the breeding life of Greater Spotted Eagles and their offspring. Among the vast amount of valuable information documented by camera traps, the greatest interest concerned breeding success and trophic characteristics, as the species composition and quantity of food collected allows for an assessment of the condition of the breeding grounds \u2013 these are marshes with varying degrees of flooding and diverse vegetation. Based on the information obtained, the main results of the 2025 breeding season in terms of the number of breeding pairs are presented.<\/p>\n\n\n\n<ul>\n<li>Pair 1. Rivne, Perebrody Massif. The pair successfully hatched one chick, which remained in the nest until 11th September 2025. The trophic diet was dominated by small rodents and reptiles (grass snake (<em>Natrix natrix<\/em>)). The main food items were voles (Microtus sp.) and water voles (<em>Arvicola amphibius<\/em>).<\/li>\n\n\n\n<li>Pair 2. Rivne, Perebrody Massif. The pair successfully hatched one chick, which remained in the nest until the 19th September 2025. The trophic composition was dominated by small rodents and waders (Charadrii). The main food source was voles, including water voles.<\/li>\n\n\n\n<li>Pair 3. R\u00f3wne, Somyne Massif. The pair successfully hatched one chick, which remained in the nest until 13th August 2025. The trophic composition was dominated by small rodents, which the adult birds brought in large numbers, but the chick did not have time to consume them. This pair specializes in hunting mustelids (Mustelidae). Therefore, this season, ermines (<em>Mustela erminea<\/em>) and weasels (<em>Mustela nivalis<\/em>) were abundant in the trophic composition.<\/li>\n\n\n\n<li>Pair 4. R\u00f3wne, Somyne Massif. This pair has failed to breed successfully every year since 2021. This year, the pair built a new nest near the old one, which had been destroyed. At the end of July, there was a single fluffy chick in the nest, which was not the typical age for this period. The chick died due to weather conditions (a downpour). It is known that chicks in the early stages of development have not yet developed thermoregulation, so they often die from hypothermia. Adult birds typically keep their chicks warm during such critical periods, but based on camera trap data, it was determined that the chick was not warmed by the adults during the downpour, which led to hypothermia. Furthermore, the female in this pair was noted to have a metal ring. It turned out that she was born in the Olman Marshes (Belarus) and was spotted with a ring in 2013 near the Perebrody massif in the border region.<\/li>\n\n\n\n<li>Pair 5. Rivne, Somyne Massif. The pair successfully hatched one chick, which remained in the nest until the 16th September 2025. The food supply, as in other pairs, was dominated by small rodents \u2013 voles, as well as galliformes (Galliformes) and hares (<em>Lepus europaeus<\/em>). This pair specialized in hunting hares, black grouse (<em>Tetrao tetrix<\/em>), hazel grouse (<em>Tetrastes bonasia<\/em>), and partridges (<em>Perdix perdix<\/em>).<\/li>\n\n\n\n<li>Pair 6. Rivne, Somyne Massif. The pair successfully hatched one chick, which remained in the nest until the 15th September 2025. This pair is quite flexible in foraging, and each year has its own characteristics. For example, in 2024, they specialized in collecting corncrakes (Crex crex) and water rails (Rallus aquaticus); in 2023, they specialized in stoats and amphibians (Amphibia); and in 2022, they specialized in fish (Pisces, Actinopterygii). In 2025, their focus was on voles and squirrels (<em>Sciurus vulgaris<\/em>). Furthermore, the pair&#8217;s nest is important for other species. After breeding, it is visited by numerous birds and small rodents, attracting predators. Successful hunting of the Great Grey Owl (<em>Strix nebulosa<\/em>) on rodents, the Eurasian Tawny Owl (<em>Strix aluco<\/em>) on the European Nightjar (<em>Caprimulgus europaeus<\/em>) and the Pine Marten (<em>Martes martes<\/em>) on the Hazel Dormouse (<em>Muscardinus avellanarius<\/em>) has been recorded. The marten is the main enemy of the Greater Spotted Eagle, destroying nests. This predator was recorded in 2025 in all studied nests.<\/li>\n\n\n\n<li>Para 7. Pripyat-Stochid Nuclear Power Plant. The camera trap was installed in July 2025. There was one chick in the nest at the time. The camera trap is still operational, so final data will be provided later.<br><\/li>\n<\/ul>\n\n\n\n<p>As a result, the authors of the <a href=\"https:\/\/raptors.org.ua\/7509\">aforementioned publication<\/a> conclude that the Greater Spotted Eagle&#8217;s main prey in <a href=\"https:\/\/sparrow.up.poznan.pl\/life\/en\/2026\/09\/04\/greater-spotted-eagle-tagging-results-in-western-polesie-in-2025\/\" data-type=\"post\" data-id=\"428\">2025<\/a> were small rodents, especially the water vole. Thanks to improved hydrological conditions in the marshes, the population has begun to rebuild. The summer of 2025 was very rainy, and water levels exceeded norms for this period. Perhaps due to the anomaly of marsh flooding, Greater Spotted Eagles hunted in drier areas and forests, as evidenced by the forest species harvested. In terms of breeding success, this was a successful year, with five of the six pairs successfully leaving the nests and establishing independent lives. The last encounters between the chicks and adults at the nests occurred in the second week of September, which is typical for these latitudes. Therefore, there is hope that the Greater Spotted Eagles successfully migrated, overwintered, and returned to their nests in the next breeding season in 2026.<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Currently, the core breeding population of the Greater Spotted Eagle (Clanga clanga) in Ukraine is concentrated in the Rivne Nature Reserve, where annual surveys are conducted to monitor various aspects of breeding biology. These surveys began in 2012, as reported in articles published on the website of the Ukrainian Center for the Study of Birds [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[57,49,25,52,56,11],"_links":{"self":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/433"}],"collection":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/comments?post=433"}],"version-history":[{"count":1,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/433\/revisions"}],"predecessor-version":[{"id":434,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/433\/revisions\/434"}],"wp:attachment":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/media?parent=433"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/categories?post=433"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/tags?post=433"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}