Adam Olszewski, Bartłomiej Woźniak, Tomasz Chodkiewicz, Jerzy Lewtak
Ornis Polonica 2010, 51: 252–261
https://doi.org/10.12657/ornis.2010.4.1
Abstract: The paper describes distribution and numbers of owls in the central part of the Kampinos National Park (KPN). The study was conducted in the years 2008–2009 within the area of 89 km² (23% of the area of KPN). In both seasons a census based on vocal stimulation was performed. Only two owl species were observed: the Tawny Owl Strix aluco and Long-eared Owl Asio otus. All observations were mapped. A total of 44–45 territories of Tawny Owls were detected during the first and second season respectively, producing the average densities of 4.9–5.1 and 4.4–4.6 territory/10 km², respectively. The Tawny Owl population reached the highest densities in tree stands more than 120 years old. The number of the Long-eared Owl territories found in 2008 was 11–12 (density 1.2–1.4 territory/10 km²). The density in a semi-open area “Mozaika” was much higher (3.1–3.4 territory/10 km²), suggesting a species preference for mosaic habitats composed of woodland and open areas. In 2009 only one territory of the Long-eared Owl was found (density 0.1 territory/10 km²). Data gathered during the study were combined with the results of earlier research to produce population size estimates for these two owl species in the whole KPN. The Tawny Owl population was estimated at 139–160 pairs and Long-eared Owl at 33–37 pairs (using data from 2008).