AVOCETTA - VOLUME 23 - N. 2
Population density and demographic trend of the Scops Owl Otus scops in the Northern Apennine (Oltrepò Pavese, Northern Italy)Sacchi R., Perani E. & Galeotti P.
Abstract:From 1992 to 1994 European Scops Owls (Otus scops) were censused in the Oltrepò Pavese, a hilly area (448 Km2 in extent) south of Pavia (Northern Italy), using the playback of tape recorded songs. In the first year 37 territories were found for an average population density of 0.08 terr./Km2 (8 territories over 100 Km2). However, Scops Owls were not regularly distributed throughout the area, but they concentrated in the town of Voghera and in the central part of the hilly area. In 1993 we observed a dramatic decline of the Scops Owl population since 21.4% of territories were not re-occupied. The decline was confirmed in 1994, when 3 other territories were lost for a total decrease of 32.1% relative to the first year of the study. The intensification of agricultural practices (namely vineyards) and the intensive use of pesticides were probably the main factors responsible for this decline.