Coincidence of Small Mammal Trapping Data with their Share in the Tawny Owl Diet

Abstract

Data for 1997–2005 on the Tawny Owl (Strix aluco) diet during the breeding period (food remains from nest-boxes after breeding) were compared with long-term (spring and autumn 1997–2004) data on small mammal monitoring and short-term trapping data obtained close to owl nest-boxes (autumn 1999 and 2000). The investigated sites were located in the Kėdainiai district (central Lithuania). A total of 18 mammal species were identified in the diet (91.3% of 2,042 identified remains). In general, mammal diversity in the diet was much higher (9 to 15 species recovered annually) than in trapping. Owls mainly preyed on bank voles (31.0% of all recovered mammals), short-tailed voles (15.8%, Microtus in total – 29.5%) and yellow-necked mice (14.6%). At the monitoring site, 969 individuals of 12 species (5 to 10 species annually) were trapped. Dominant was the bank vole (47.6%), followed by the yellow-necked mouse (18.7%) and common vole (14.1%, Microtus in total – 16.4%). A total of 193 individuals of 9 small mammal s...