Interspecific relations of parasites of bank vole Myodes glareolus (Schreber, 1780)

The material for the investigation was collected in Southern Karelia for the period of 1998–2000. The host sample consisted of 384 specimens of bank vole. Correlation analysis was applied for quantitative data: parasite abundance in the host. Co-occurrence of species (presence-absence data) were estimated by the C-score index (Stone, Roberts, 1990). Calculations were carried out using the program EcoSim (Gotelli, Entsminger, 2004). We observed 38 parasite species belonging to 6 taxonomic groups. The core of the bank vole parasite community (93 % of all collected bank vole parasites) was represented by 11 species: Heligmosomum mixtum, Heligmosomoides glareoli, Syphacia petrusewiczi (nematodes), Ixodes persulcatus, I. trianguliceps (ticks), Hirstionyssus isabellinus, Eulaelaps stabularis, Haemogamasus nidi (gamasid), Ceratophyllus rectangulatus, Leptopsylla silvatica, Ctenophthalmus uncinatus (fleas). Adaptation to coexistence had a tendency to the balancing of a pathogenic action of a parasite complex with an immunophysiological status of the host. The observed frequency distribution of the number of parasites in the bank vole complies with a lognormal distribution (Fig. 1). The analysis of co-occurrence of bank vole parasites showed that the presence or absence of one parasite in the host does not affect the presence of another. The results on the co-occurrence of parasites indicate that they don't influence each other negatively (Table 1). Correlation of abundance in the concurrent infections were statistically reliable (p