Molecular Identification of Selected Cervid Helminths in Supplementarily Fed European Bison Population

Background: Wild animals often suffer from infections with multiple species of parasites simultaneously. The exchange of parasites between different host species is common in nature and often involves intermediate hosts or sharing space such as pastures or watering holes. Supplementary feeding, leading to large aggregations of individuals, can have several adverse effects on wild ungulate populations, despite being a widespread management practice. One such effect is an increased risk of parasitic infections, particularly in social animals. We quantified the prevalence of selected helminths typically found in cervids, in samples of the European bison faeces, using molecular methods, and compared endoparasite species richness between supplementarily fed and nonfed European bison herds in the Białowieża Primeval Forest, NE Poland. Methods: Using the diagnostic PCR method, we analysed the faecal samples for molecular markers of nine parasite species which are typically found in cervids: moose, red deer, and roe deer. Results: All analysed samples tested positive for at least one parasite species, and the average number of parasite species per sample was 3.2. The most prevalent parasites were gastrointestinal nematodes: Ostertagia leptospicularis and Ostertagia antipini, found in 89.2% and 50.6% of the European bison faecal samples, respectively. We found significant differences in the prevalence of four parasite species between supplementarily fed and nonfed European bison herds. Co-occurrence analysis showed that most of the associations between parasite species pairs were random. Conclusion: Management practices, such as supplementary feeding, can influence the spread of parasite infections in social mammals. This study also promotes the application of molecular methods for noninvasive parasitological monitoring of wildlife populations of endangered ruminant species sharing resources with other ungulates.