Small mammal community in a Mediterranean target area of Sicily by the data from the long-eared owl pellets

The present study was carried out through analysis of bone remains in 1003 long-eared owl pellets of Asio otus (Strigiformes, Strigidae). The investigated area is in the Southeastern slope of Mount Etna (Sicily) outside the boundary of Etna Park. A total of eight species were found of ten species known for the whole Sicily, such as Microtus nebrodensis (Rodentia, Cricetidae), Apodemus sylvaticus, Mus domesticus, Rattus rattus, Rattus norvegicus (Rodentia, Muridae), Eliomys quercinus (Rodentia, Gliridae), Suncus etruscus and Crocidura sicula (Soricomorpha, Soricidae). The most frequent species among the total specimens found in the long-eared owl pellets was vole M. nebrodensis with a frequency of 75.24% and composed of 57.54% of a biomass in analysed habitats. The second most frequent species was A. sylvaticus with a frequency percentage of 13.23%, but participates third place in the assessed biomass (10.52% of the biomass), thereas the more masses species R. norvegicus composed of 29.29% of the biomass and with a frequency of 7.47% in the owl pellets. The high number of species found (eight species out of ten known for the Sicilian small mammal fauna), and the medium-low diversity values (Gini-Simpson = 0.41; Shannon-Weaver = 0.64) are likely to be attributed to the fragmentation of habitats and consequent ecotone effect. The high value of the Cricetidae/Muridae ratio and the low value of the trophic level index (Soricidae/Rodentia ratio) highlight a type of agricultural anthropization. The composition and structure of the studied small mammal community confirmed a consolidated medium-high level of agricultural anthropization in a landscape characterized by a mosaic of rural and natural environments. However, the importance of these agro-ecosystems depends on the high number of small mammal species present, including some of conservation interest.