{"id":474,"date":"2026-09-27T16:57:53","date_gmt":"2026-09-27T14:57:53","guid":{"rendered":"https:\/\/sparrow.up.poznan.pl\/life\/en\/?p=474"},"modified":"2026-09-27T16:57:53","modified_gmt":"2026-09-27T14:57:53","slug":"monitoring-of-greater-spotted-eagle-nesting-in-the-rowne-reserve","status":"publish","type":"post","link":"https:\/\/sparrow.up.poznan.pl\/life\/en\/2026\/09\/27\/monitoring-of-greater-spotted-eagle-nesting-in-the-rowne-reserve\/","title":{"rendered":"Monitoring of Greater Spotted Eagle nesting in the R\u00f3wne Reserve"},"content":{"rendered":"\n

Research on the breeding population of the Greater Spotted Eagle (Clanga clanga<\/em>) in the R\u00f3wne Nature Reserve has been ongoing for many years, as reported by M. Franchuk, A. Simon, S. Domashevsky, and V. Kaystro<\/a>. Monitoring involves assessing the breeding status of known and potential nesting sites regarding nest occupancy, reproductive success, diet, and the marking of chicks. Work in 2020 was conducted in two stages:<\/p>\n\n\n\n

    \n
  1. (the second and third ten-day periods of July): This stage involved inspecting known and potential Greater Spotted Eagle nesting sites, as well as marking birds with color and metal rings and GPS-GSM transmitters. A total of 10 nests were checked during this stage. Five of the nests were found to be occupied, each containing a single Greater Spotted Eagle chick (two nests in the Perebrody tract, three in the Somyne tract of the reserve).
    Additionally, one nest (belonging to a mixed pair in the Syra Pohonya tract of the reserve) was occupied by a Great Grey Owl (Strix nebulosa<\/em>). The remaining four nests (three in the Perebrody tract and one in the Somyne tract) were unoccupied; one was abandoned because the species had been displaced from its breeding territory by a White-tailed Eagle (Haliaeetus albicilla<\/em>), which had built a new nest 50 m away from a known Lesser Spotted Eagle nest. The Greater Spotted Eagle likely relocated 2 km to the north, where it was regularly recorded between May and July 2020.
    Three Greater Spotted Eagle chicks were spotted in the Perebrody and Somyne areas. Unfortunately, attempts to sight the adult birds at that stage were unsuccessful. The entire research phase was hampered by difficult weather conditions. Due to unusually heavy rainfall, water levels in the marsh reached a critical point, and almost all visits to the nests required wading through waist-deep water over long distances. The team also encountered a prolonged downpour.
    Two pairs relocated from their previous year’s nesting sites \u2014 one due to nest destruction and the other because of frequent visits by pine martens (Martes martes<\/em>), as evidenced by data from a camera trap installed at the nest before the breeding season began. Thanks to the Ukrainian researchers’ expertise, the new nests were easily located, though this entailed an additional 5\u20137 km of arduous trekking through the marsh.
    Concurrently, the Ukrainian team collected trophic material (pellets and animal remains such as skulls, skeletons, and feathers) and took feather samples for genetic analysis to determine the extent of hybridization between the Lesser Spotted Eagle (Clanga pomarina<\/em>) and the Greater Spotted Eagle. Prey items found included the grass snake (Natrix natrix<\/em>), water rail (Rallus aquaticus<\/em>), common snipe (Gallinago gallinago<\/em>), great reed warbler (Acrocephalus arundinaceus<\/em>), European mole (Talpa europaea<\/em>), American mink (Neovison vison<\/em>), and field vole (Microtus agrestis<\/em>).
    Camera traps were installed at two nests where chicks had been observed.<\/li>\n\n\n\n
  2. (late August): this phase involved attempts to capture and tag adult greater spotted eagles in the reserve within the Somyne massif. Rain on the morning of the first day prevented operations. The following day, two capture sites were successfully set up, spaced several kilometers apart and corresponding to the hunting grounds of two neighboring pairs. One chick from these two pairs had been fitted with a GPS-GSM transmitter during the first stage, so it was known that the bird had been flying for some time and was a strong flyer. The chick from the second pair had been the youngest of the five studied during the July surveys (based on a visual assessment of down-to-feather replacement), raising hopes that the parents would continue to feed it actively. The first bird captured was the male from this pair. Morphologically, the bird appeared to be a typical greater spotted eagle, consistent with this type of habitat. It was fitted with metal and plastic rings and a GPS-GSM transmitter.
    No greater spotted eagles were sighted for an extended period in the hunting grounds of the first pair. Only occasionally did sounds resembling the cries of a young bird begging for food drift from the marsh opposite the nesting site. However, a few hours later, the bird appeared near the observation point. It circled over the marsh, spotted potential prey, and began to descend toward it, only to disappear behind the reeds where a trap had been set. The attempt to capture it, however, was unsuccessful. Nevertheless, a transmitter was spotted on the back of the departing bird. This could mean only one thing: the chick from the first pair \u2014 recorded back in July \u2014 had not only successfully fledged and was flying proficiently but was also capable of hunting independently, a skill essential for an autonomous life.
    On the third day, the Ukrainian team visited the third pair in the Somino massif. Despite attempts, the bird could not be caught.<\/li>\n<\/ol>\n\n\n\n

    In 2020, a total of six greater spotted eagles were ringed (five chicks and one adult), with three of the chicks and the adult bird being fitted with GPS-GSM transmitters. All the chicks successfully fledged and began their autumn migration. The adult bird carrying a transmitter also commenced its autumn migration. This indicates that all the birds fitted with transmitters are alive and capable of long-distance movement.<\/p>\n\n\n\n

    Research findings from 2017\u20132018 can be found in a separate report<\/a> on the website of the Ukrainian Bird of Prey Research Centre<\/a>. Results from subsequent studies have been published for the years 2023<\/a>, 2024<\/a>, and 2025<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Research on the breeding population of the Greater Spotted Eagle (Clanga clanga) in the R\u00f3wne Nature Reserve has been ongoing for many years, as reported by M. Franchuk, A. Simon, S. Domashevsky, and V. Kaystro. Monitoring involves assessing the breeding status of known and potential nesting sites regarding nest occupancy, reproductive success, diet, and the […]<\/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":[82,57,49,26,78,25,50,48,83,11],"_links":{"self":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/474"}],"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=474"}],"version-history":[{"count":1,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/474\/revisions"}],"predecessor-version":[{"id":475,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/posts\/474\/revisions\/475"}],"wp:attachment":[{"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/media?parent=474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/categories?post=474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sparrow.up.poznan.pl\/life\/en\/wp-json\/wp\/v2\/tags?post=474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}