[In Polish] The process of becoming independent in the post-fledling period of the telemetry tracked White-tailed Eagles Haliaeetus albicilla from the Bory Tucholskie National Park
In 2019–2020, as part of the research on the spatial ecology of the White-tailed Eagle in the “Bory Tucholskie” National Park (PNBT), 4 GPS loggers were given to large chicks. In 2019, chicks from two different nests were equipped with these devices, and in 2020, another two chicks from the same nests. It has been shown that the dispersion of juvenile White-tailed Eagles is preceded by a preparation period lasting several weeks, during which large chicks go through several characteristic stages: weakly volatile pod flying on the branches, short training flights outside the nest, directed flights to the feeding grounds (<3 km) and long-distance (>3 km) exploration flights. The first flights of the examined individuals outside the nest area were made between the 6 th and 13 th July, while the first flights to the feeding grounds occurred between the 28 th July and 7 th August. All tracked individuals began longer exploratory flights (N=64, X=16), with a maximum distance of 43.2 km from the nest (X=11.76 km, Me=10.01 km) between the 9 th August and 1 st September. In both years of study, the young birds from the same breeding area left the nest and its surroundings in the third week of August and moved 1,300 m to the NE, to the peninsula of the main lake in the Park. Juvenile White-tailed Eagles from the “Bory Tucholskie” National Park began their independence period between the 5 th and 22 nd October. During the first 30 days from the moment of leaving the breeding area, juveniles left the Park in various directions travelling for distances of 39–80 km, using strategies of abrupt displacement and nomadism, gradually exploring the feeding grounds.