Damian Wiehle, Piotr Sobas
Ornis Polonica 2018, 59: 107–118
https://doi.org/10.12657/ornis.2018.2.1
Abstract: The paper presents the current distribution and numbers of the Ural Owl Strix uralensis within the area of the Niepołomice Forest. During each of three breeding seasons (2015–2017) three night counts were conducted between February and April. The second stage included daily visits of sites where the species had been heard at night. Daily visits were carried our between 10 March and 20 April (a total of 22 visits in 2015–2017). Numbers of breeding territories in consecutive study years were: 2015 – 29, 2016 – 21 i 2017 – 25. Considering the past data, the population can be classified as stable. In 2015–2017 1–3 breeding territories (0.65–1.96 pair/10 km2) were found in the complex “Grobla”, as well as 1–3 sites which might have hosted breeding pairs. In the complex “Bór” 8–15 confirmed breeding territories (0.90–1.70 pair/10 km2) and 10–14 potential breeding sites were recorded. No territory was found in complexes “Grobelczyk” and “Koło”, located outside the SPA Natura 2000. This research confirmed a strong breeding territory fidelity of the species. The analysis of distribution of breeding territories indicated the species showed preferences for old-growth forests. The highest breeding densities were found in the areas representing a mosaic of unevenly aged stands, with dominating old-growth forests but also patches of forest nurseries, sapling stands and clearings. The analysis of map clusters revealed that some parts of the Niepołomice Forest contained potentially good breeding habitats, but they were not occupied by the species. This probably resulted from the close proximity to human settlements and the highway A4 in the south of the area.
Keywords: distribution, GIS layers, map clusters, numbers, Strix uralensis, the Niepołomice Forest, Ural owl
