Do the Contents of Barn Owl Pellets Accurately Represent the Proportion of Prey Species in the Field

摘要: Prey composition of Barn Owl (Tyto alba) pellets from northwestern Negev, Israel, was ex- amined. The 414 individual specimens mammals represented by 256 comprised: 9.2% Meriones sacramenti, 41.1% M. tristrami, 8.2% Gerbillus an- dersoni, 40.1% Mus musculus, and 1.4% Crocidura suaveolens. also contained some remains insects, small the snake Ery.x jaculus, two passerine birds. We tested whether ob- served distribution prey species in could be obtained if owls hunted at random. Direct calculation simulations indicate that more single- large than would expected random sampling. In simulation sampling database, dis- tribution "pellets" containing 1, 2, 3, or items similar to observed only when a cumulative weight limit for pellet ejection set SO-100 g. Even Owls do not hunt preferentially, contents may biased towards larger prey. This result should taken into consideration accumulated are used ecological paleontological studies approximate mammal real communities, present past.