Coexistence in Helminths of the Bank Vole Clethrionomys glareolus. II. Intestinal Distribution and Interspecific Interactions

We studied the intestinal distribution of helminths (cestodes and nematodes) in the bank vole Clethrionomys glareolus, and changes in distribution due to the presence and varying abundance of other species. The material was obtained from two localities in Finland: Pallasjarvi in western Lapland and Lammi in southern Finland. 2. The intestinal distribution of the common species Heligmosomum mixtum (Nematoda) was affected by the rare species Capillaria sp. (Nematoda) and Paranolocephala gracilis (Cestoda). The common species showed inconsistent negative interactions with other common species. 3. The data indicate that interactions between the intestinal helminths of the bank vole are most likely to occur between species with large intestinal overlap, but not necessarily feeding overlap