SUMMER FOOD OF THE PYGMY OWL GLAUCIDIUM-PASSERINUM IN BIALOWIEZA-NATIONAL-PARK, POLAND

Analysis of 52 pellets of the Pygmy owl Glaucidium passerinum (L.) col lected during the summer in the primeval forests of Bialowieza Nationa l Park (BNP) in eastern Poland revealed 118 prey items and showed that the diet of owls was composed of birds (69% of prey number, 73% of pr ey biomass) and small rodents (31% of prey number, 27% of biomass). Of the two most numerous rodents, the bank vole Clethrionomys glareolus was captured more and the yellow-necked mouse Apodemus flavicollis les s than would have been expected from their availability as measured by trapping. The most numerous avian prey of the Pygmy owl were the Grea t Tit Parus major, the Robin Erithacus rubecula, the Chaffinch Fringil la coelebs, and Carduelis spp. A comparison with the community of bree ding birds revealed that finches Carduelis spp. and tits were selected by owls. A literature review on the Pygmy owl's preying preferences o n passerines showed that this predator had clear seasonal, but little geographic variation in its preferences for bird prey within Europe.