Abstract: Parasites diversity in close-related species of hosts may be different depending on habitat use and climatic conditions. The aim of this study was to
analyze parasites fauna in four felid species inhabiting Russian Far East and South Siberia (including taiga forest and mountain treeless areas). We
have collected 272 feces samples of four felid species: Amur tiger, Amur leopard, snow leopard and Pallas� cat. Helminths (eggs and larvae) in
excrements were studied by flotation using a saturated solution of ammonium nitrate. We have described 10 helminths species in Amur tiger feces, 6
� in Amur leopard, 2 � in snow leopard and 3 � in Pallas� cat. Obviously, snow leopard and Palls� cat had lower helminths diversity than two other
species. These differences can be explained, to some extent, by climatic parameters. The climate in the snow leopard and Pallas' cat habitats is
described by sharp and significant temperature fluctuations – the annual temperature difference can exceed 90°C, which may lead to lower survival of
the number of infectious agents in Pallas' cat excrements. In addition, the snow cover that can protect helminth eggs and larvae from the cold
temperatures especially in Amur tiger and Amur leopard habitats. Possibly, another important factor is the spatial and social organization of Pallas'
cats, with a low frequency of contacts with other individuals. Such way, species-specific differences in helminths were related, probably, with the
species evolution in different habitats