On the food of the Eurasian pygmy owl (Glaucidium passerinum) in Slovakia

Data on the food of the Eurasian pygmy owl in Slovakia was collected in 1999−2014 at 12 breeding locations in 7 mountain ranges of the Western Carpathian Mts and 1 range belonging to the Eastern Carpathian Mts. The basis of the evaluation of the food spectrum of prey of G. passerinum was the collection of pellets, osteological remnants and feathers from birds beneath nest cavities and roosting places of females in the months of May to July, that is, in the period of feeding young in the nest. Overall samples of food from 12 nests at elevations of 650−1,260 m a.s.l. were collected; from the largest of the three nests in the upper Nitra Region, from one nest in the Západné Tatry Mts and from three nests in the Volovské vrchy Mts. We compared these data with existing published data from Slovakia. A higher share of birds (65.0%) was found in the obtained material than mammals (34.8%). In the samples from 12 locations 10 species of mammals and 33 species of birds were found among the 377 individual prey samples. Among mammals, forest species of rodents predominated: Clethrionomys glareolus (22.8%) and Apodemus flavicollis (6.6%). The species Microtus arvalis (2.7%) was less abundant than in the stores of food from the Chocské vrchy Mts (35.4%). From the broad spectrum of songbirds, no species exceeded a presence of 7%. Species from the families Sylviidae, Turdidae, Paridae and Fringillidae were more numerous, while the species Phoenicurus phoenicurus, Motacilla alba, Carduelis cannabina, Dendrocopos minor and Passer domesticus were among the more uncommon prey. In total 582 individual prey were determined from the food remnants of G. passerinum in Slovakia (present study and other published studies). The species Clethrionomys glareolus occurred with a higher dominance than average in the pellets of G. passerinum in the mountains which border the region of the upper Nitra. In the Belianské Tatry Mts the most abundant rodent species was Terricola subterraneus, while in the mountains of eastern Slovakia the yellow-necked mouse Apodemus flavicollis was most often hunted, and of the songbirds, the coal tit Periparus ater. Among songbirds hunted near the breeding grounds of G. passerinum in the Považský Inovec Mts the collared flycatcher Ficedula albicollis was the most numerous. Among the most numerous songbirds which are evenly represented in all compared areas were: Regulus sp., Certhia familiaris, Poecile montanus and Cyanistes caeruleus.