The unfavorable epizootic situation on nematode infestation of populations of the sable Martes zibellina and the pine marten M. martes in Western Siberia

Objective of research: to study the nematode infestation of the sable and pine marten in Western Siberia. Materials and methods: Altogether 169 individuals of the sable and 18 — of the pine marten were investigated using the method of partial dissection of the gastrointestinal tract and lungs. Animals were caught according to the hunting license in 2009-2011 and 2014-2015, in 8 areas of Western Siberia from the south taiga to the northern forest-steppe. Results and discussion: We have found four species of parasitic nematodes, two of which (Crenosoma petrovi, Filaroides martis) were localized in lungs and two species (Capillaria putorii, Strongyloides martis) — in the intestine of the sable and the pine marten. Prevalence of lung nematodes was 80%, intestine nematodes — 40%. Intensity of infestation ranged from 26 to 358 nematodes per animal. F. martis is the most pathogenic and most common helminth in martens in Western Siberia. 53,3% of pine martens and 26,5% of sables were infected with this nematode species. Nematode S. martis is the most abundant in the intestine. In pine martens the extensity of invasion was 42,8%, the abundance index — 8.29 helminths per animal; in sables — 9,1% and 1.18, respectively. Pine martens were infected by F. martes and S. martis more than sables (p — 0,05). Prevalence increases in the direction from the North East (taiga) to the South West (sub-taiga), which determines the intensity of the helminthiases focus in biocenoses of Western Siberia. Infection of pine martens in the forest-steppe was not detected. In 2014–2015 compared with the previous study period (2009–2011) the extensity of invasion with intestinal nematodes increased by 1,5–2 times, and with highly pathogenic lung parasites — by 3 times. The increase in the helminth infestation may be explained by the growth of animal population density.