Parameters of the Autumn Migration Stopover of Young Bluethroats (Luscinia svecica Linnaeus, 1758) in the Conditions of the Middle Taiga in the Eastern Russian Plain.

In 2015–2019, young bluethroats were caught in order to determine the parameters of their migration stop in the taiga zone in the east of the Russian Plain. A total of 272 birds were analyzed, of which 186 were males and 86 were females. The average duration of the migration stop for young bluethroats was 1.45 days. Transient individuals have fat reserves that allow them to make migratory jumps lasting an average of 4.39 ± 0.20 h. Bluethroats with an average stopping time have a mass deposition rate of 0.04 ± 0.36 g per day and, by the time of departure, are able to make nonstop flights lasting an average of 3.89 ± 0.58 h. Individuals that make the decision to stop lose a little of their fat reserves, reducing their ability to fly nonstop until the next stop. The significance of the river valleys in the east of the Russian Plain for a successful stopover remains an open question, and it has not been fully clarified whether these places have the necessary ecological conditions for the successful stopover of small birds. [ABSTRACT FROM AUTHOR]