The occurrence of owls on 6 census plots (total of 80 km²), situated on agricultural areas of the Mazowsze Lowland (Fig. 1) in the Eastern part of Central Poland, was studied. The investigated area comprised 3 physiogeographical regions (Table 1 and Fig. 2-7). The studies were based on the mapping method (Domaszewicz et al. 1984). 2-4 owl species were found on each plot (Table 2). Asio otus was dominant on cultivated fields and small young pine woods, and Athene noctua was dominant on fields and meadows with numerous headed willows. Asio otus densities in the Wysoczyzna Siedlecka region (Fig. 1) were low and differences between years were insignificant (1 pair/10 km²). In the other areas large population fluctuations of this species (0 up to 5.1 pairs/10 km² on one plot), were recorded. Density of Athene noctua in plots situated in regions of Wysoczyzna Siedlecka and Równina Warszawska (Table 2) was 0-2 pairs/10 km², whereas in the region Kotlina Warszawska it did hot exceed 6.8 pairs/10 km². The density of Strix aluco was found within the range 0-2.6 pairs/10 km². The density of Asio otus, Strix aluco and Athene noctua (outside the region Kotlina Warszawska) were similar to data from Central Europe. Densities of Tyto alba and Athene noctua (in region Kotlina Warszawska) were relatively high. The number of population of Strix aluco, Athene noctua and Tyto alba decreased during the study period. Strix aluco and Asio otus occurred in small woods surrounded by fields as well as in larger forests of the areas 16-200 ha and 0.1-200 ha, respectively. Besides, nesting of Asio otus on single trees and in alleys with headed willows, and of Strix aluco in riverine type woods, of area 3 and 5 ha, was recorded. Analysis of distribution of territories of Athene noctua indicated strong preferency to human settlements, in the vicinity of which ca 70% of pairs were found. Such a phenomenon was not observed in the other species - only 28% of territories of Asio otus and 7% of territories of Strix aluco were found in the vicinity of human settlements.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.