Grzegorz Neubauer, Piotr Zieliński, Jakub Typiak, Artur Niemczyk
Ornis Polonica 2017, 58: 26–34
https://doi.org/10.12657/ornis.2017.1.2
Abstract: The paper presents results of a recent estimate of the Bluethroat population in the Jezioro Karaś nature reserve (N Poland), formerly one of the most important breeding areas of the species in Poland. The population size in the reserve was estimated at 120 pairs in the early 1990s, and at 75–90 pairs in mid 1990s. In 2015 three surveys were performed in May–June, covering most (May) or the whole (June) area containing habitats suitable for the species. Most of the reserve area comprises habitats currently inadequate for Bluethroat due to drainage and ongoing plant succession. Except for a single male, all Bluethroats occupied a narrow belt of willow Salix spp. rushes between the lake water table and alder carrs surrounding the lake. Only 9 and 7 males were recorded during the surveys in May and June, respectively. After correcting for an imperfect detection, the population size has been optimistically estimated at 10 males (95% confidence intervals: 7–30), indicating the drastic decline since the 1990s.
Keywords: Bluethroat, decline, Karaś Lake, Luscinia svecica, population size
