Somogyi Múzeumok Közleményei 14. (2000)

Lanszki J. – Körmendi S. 2000: Ragadozó emlős közösség táplálékösszetétele a Boronka-melléki Tájvédelmi Körzetben, Somogy megyében

376 LANSZKI JÓZSEF - KÖRMENDI SÁNDOR eus), yellow-necked field mouse (Apodemus flavicollis), striped field mouse (Apodemus agrárius), (Apodemus microps) bank vole (Clethrionomys glareolus). The species observed in the quadrats were squirrel (Sciurus vulgaris) and water-shrew. (Neomys fodiens) Other Carnivora species observed on the Boronka area are stoat (Mustela erminea), and European polecat (Mustela putorius) and wild cat (Felis silvestris), but the number of scats collected was too low. To express the relative frequency of food components per category the smallest values were taken into consideration in each case. The data obtained in two years were handled as one data set in the evaluations. Seasons, however, were used as group-forming criteria in data processing. Results and discussion Small mammals formed the most important food for red foxes in winter, spring and autumn (Table 1, Figure 1). The most commonly occuring species were bank vole (Clethrionomys glareolus) and wood mice (Apodemus spp.). In addition insectivores, muskrat (Ondatra zibethicus) in spring and squirrel (Sciurus vulgaris) and fat dormouse (Glis glis) were also identified. In winter and early spring when food was rather scarce carcasses of deer (Cervidae) and wild boar (Sus scrota) served as „prey", among others. The occurrence of birds was highest in winter and decreased gradually until autumn. Particularly small-bodied songbirds (Passeriformes) but also pheasants (Phasianus colchicus) and - mainly in spring - waterfowl were components of the foxes' food. Basically grass snake (Natrix natrix) and frogs (Anura spp.) were present in the food only in spring and summer and fish species only in winter. The consumption of invertebrates was insignificant in winter but significant from spring to autumn (23.3 to 42.2%), including a wide range of species, with a Carabidae dominance. Red foxes ate corn and a variety of grasses in winter and spring and fruits (esp. Pirus spp.) in summer and autumn. In the food of pine martens the dominant components were small mammals (esp. C. glareolus) from autumn to spring, but Apodemus spp., Insectivora spp. and G. glis were also present (Table 1, Figure 1). The consumption of carcasses in winter and spring (Cervidae, Sus scrofa) and the lack of birds in the food in winter are worthy of note. For the rest of the year the bird components were mainly Passeriformes. N. natrix, Anura spp. and some fish species were also present. Invertebrates formed a substantial proportion of the food throughout the year (20.0 to 33.9%). Carabidae and leaf-horned beetles (Lamellicornia spp.) were found to be the most common components. Invertebrates were present in a rich variety (19 species). The plant food of martens (mainly fruits) played a considerable role (25.2 to 31.0%) in summer and autumn. Badgers ate much plant food (52%) in winter, particularly corn grain available from the wild boar feeders, since there was no agricultural cultivation in the area in question. For the rest of the year plants no longer played an important role in the nutrition of badgers. Millipedes (Diplopoda spp., 23%) and animal carcasses (Cervidae) were significant food components in winter (Table 1, Figure 1). Invertebrates dominated in the food supply in spring (72.9%) and in summer and autumn (combined 67.6%). The most frequent components were Carabeidae, scarabs (Scarabeidae), social wasps (Vespidae) and ringworms (Annelida spp.). The presence of small mammals and birds was insignificant. Amphibians, however, occurred in significant numbers, particularly in spring. In these habitats the most common frog species were common toad (Bufo bufo) and agile frog (Rana dalmatina). In summer, eggs of marsh tortoise (Emys orbicularis) were also detected in the food of badgers. The dominant food of otters was fish, irrespective of season (67 to 91%) (Table 1, Figure 1). Birds formed a small proportion of the food (Passeriformes and waterfowl, 0.3 to 5.5%). Anura spp. consumption was significant in spring and summer (11.9 and 12.6%, resp.). Among invertebrates the most common food component was water tiger (Dytiscus marginális). Not only water-linked species, e.g. dragonflies (Odonata spp.), decapods (Decapoda spp.), freshwater hoppers (Gammarus spp.) and ram's horn (Planorbis planorbis) but also terrestrial species living in the forests surrounding the ponds were present, e.g. violet ground beetle (Carabus violaceus) and cockchafer (Melolontha melolontha). The numbers of food taxons eaten by the predators and distinguishable to the evaluators on the basis of scat analysis were: 23 vertebrates, 15 invertebrates and 13 plants in red fox, 16 vertebrates, 19 invertebrates and 10 plants in marten, 11 vertebrates, 22 invertebrates and 7 plants in badger and 17 vertebrates, 10 invertebrates and 4 plants in otter. Acknowledgements The authors appreciate the cooperation of the Somogy Nature Conservation Organization. They thank György Rozner for participating in the identification of invertebrates included in the food of badgers. This research project was supported by the Hungarian Research Fund (OTKA, no.: F23057).