During the current century, 88 species of parasites have been recorded in Bison bonasus. These are 22 species of protozoa (Trypanosoma wrublewskii, T.

N. anomalus. The prevalence and diversity of blood parasites were lower in shrews than small rodents. Totally, 52.0% of bank voles, 50.0% of root voles, 32.5% of common shrews, and 41.2% of Eurasian water shrews were infected with any of the blood parasites. Mixed infections were seldom observed in bank vole (17.3% of investigated individuals) and root vole (14.7%). No animals were infected with three or four parasites simultaneously. Infection of Białowieża small mammals with haemoparasites seemed to be similar to those described in other temperate forest regions rather than boreal ones. Infection rates of rodent species seem to be higher in their typical habitats: for bank vole it was the highest in mixed forest, whereas for root vole in sedge swamp. The results suggest that Microtidae play a greater role than 1956, Lachmajer 1959, Wegner 1959 and helmints (Kisielewska 1963(Kisielewska , 1964(Kisielewska , 1970. The first study of blood parasites were made in mid-1990s only (Karbowiak et al. 2002). Blood parasites of shrews have not been reported from Poland before; however, there are reports from elsewhere (eg Laakkonen 2000).Białowieża Forest is one of the last primeval forest complexes in western and middle Europe. Moreover, it is an especially interesting place for biological investigations due to the geographical location on the borderland of the boreal and temperate forest zones. This fact results in the mix of fauna and flora from both zones (Faliński 1968, Gutowski and Jaroszewicz 2001. For example, among small mammals, masked shrew Sorex caecutiens -a boreal species -reaches its south-western limit in this area, whereas for Mediterranean water shrew Neomys anomalus and bi-coloured white-toothed shrew Crocidura leucodon, Białowieża Forest is the north-eastern boundary (Pucek 1981, MitchellJones et al. 1999. The same can be expected for ecto-and endoparasites of small mammals.A typical taiga tick, Ixodes persulcatus, has its western limit in Belarussia and Lithuania, however single findings were noted in Białowieża (Siuda 1993). Therefore, we expected the differences in the structure or biological features of blood parasite fauna in comparison with other parts of Europe.The aims of this study were: (1) To describe the protozoan parasites living in the blood of small rodents and shrews. A mixture of parasitological faunas typical for boreal and temperate forest zones was expected. (2) To compare prevalence and diversity of blood parasites in shrews and rodents. Higher prevalence and diversity were predicted in rodents because they are more social than shrews (Eisenberg 1966, Crook et al. 1976, Rychlik 1998, so more frequent parasite exchange should occur in rodents. (3) To investigate parasite 3 infection levels in different habitats. A higher prevalence was expected in habitats optimal for given species, due to higher densities of conspecifics and thus a higher risk of parasite transmission. Material and methodsOne-week trapping sessions of small rodents and shrews were conducted in four areas: Captu...

During the last century the recorded parasite fauna of Bison bonasus includes 88 species. These are 22 species of protozoa, 4 trematode species, 4 cestode species, 43 nematode species, 7 mites, 4 Ixodidae ticks, 1 Mallophaga species, 1 Anoplura, and 2 Hippoboscidae flies. There are few monoxenous parasites, the majority of parasites are typical for other Bovidae and Cervidae species and many are newly acquired from Cervidae. This is an evident increased trend in the parasite species richness, in both the prevalence and intensity of infections, which is associated with the bison population size, host status (captive breeding or free-ranging) and the possibility of contact with other ruminant species. In light of the changes to parasite species richness during the last decades, special emphasis shall be given to new parasite species reported in European bison, their pathogenicity and potential implications for conservation.