Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Horváth, Győző, Molnár D., Németh Tamás - Csete Sándor: Landscape ecological analysis of barn owl pellet data from the Drava lowlands, Hungary - A Dráva menti gyöngybagoly köpetekből nyert adatok tájökológiai elemzése

HORVÁTH ET AL.: ECOLOGICAL ANALYSIS OF BARN OWL PELLET DATA 181 November, including any possible second nesting. If pellets were collected several times in a particular nesting area, then their data were treated together within that period. Small mammal identification was done according to SCHMIDT (1967), Ács (1985) és ÚJHELYI (1994), based on skull characteristics and tooth morphology. Some identification guides differentiate Neomys species - Neomys fodiens (Pennát, 1771) and Neomys anomalus (Cabrera, 1907) - based on the height of the coronal process of the mandible. Withtin the genus Apodemus, we treated the wood mouse Apodemus sylvaticus (Linnaeus, 1758), yellow-necked wood mouse Apodemus flavicollis (Melchior, 1834) and the pygmy field mouse Apodemus microps (Kratochvíl és Rosicky, 1952) together as wood mice {Apodemus spp.). The differentiation of the two Mus species occurring in Hungary, i.e. the house mouse {Mus musculus Linnaeus, 1758) and the gleaner mouse {Mus spicilegus Petényi, 1882) from owl pellet skeletal remains is still not totally settled. These two species were then separated based on the upper and lower zygomatic arches (DEMETER 1995, DEMETER et al. 1995). If these were either missing or only mandibles were present, then only the genus was determined {Mus spp.). Hereby is a list of taxa that are determined in pellet analyses at non-species lebvels (only small mammals are considered): Soricidae indet. (any unidentifiable shrew) Neomys spp. {Neomys fodiens or N. anomalus) Apodemus [Sylvaemus] spp. (any species belonging to the Sylvaemus subgenus - sylvaticus or flavicollis or microps) Mus spp. {musculus or spicilegus) Rattus spp. {rattus or norvegicus). For landscape ecological analysis CORJNE LANDCOVER 1:50.000 mapping categories were applied, based on which we determined 17 patch categories differing in their qualities from the aspect of barn owl hunting. Using the software Arc View 3.2 the following patch types were established: waters, wet areas (marshes), forests (closed or Table 1: UTM codes, sample numbers, pellet numbers and prey abundance values for the 17 villages selected Nesting sites UTM codes Number of samples Number of pellets Total number of individuals Upper reach 1. Zákány XM52 3 299 747 2. Gyékényes XM52 3 42 118 3. Porrogszentkirály XM52 4 339 1017 Middle reach 4. Berzence XM62 2 39 116 5. Somogyudvarhely XM61 2 130 410 6. Vízvár XM70 3 48 157 7. Heresznye XM70 1 38 152 Lower reach 8. Drávafok YL18 6 196 409 9. Drávaiványi YL18 2 14 45 10. Zaláta YL27 3 136 406 11. Nagycsány YL28 5 150 415 12. Piskó YL27 5 115 306 13. Vejti YL37 6 162 422 14. Vajszló YL38 5 130 294 15. Páprád BR68 7 184 305 16-Cún BR77 2 72 160 17. Szaporca BR77 3 112 328 Total 62 2206 5807