Patterns of parasite species richness of Western Palaeartic micro‐mammals: island effects

Abstract

We investigate the patterns of parasite species richness of small mammals of the Western Palaearctic, and the effects of insularity. We compiled 28 studies dealing with 16 species of mammals. There was a significant effect of area size on the total parasite species richness, controlling for host sample size. Four mammal species were sufficiently sampled. Two are associated with humans: Mus musculus, and Rattus rattus , and two are not associated with humans, Apodemus sylvaticus and Clethrionomys glaerolus. We show that there is an effect of insularity on parasite species richness of A. sylvaticus . Rodents associated with humans show no effect of insularity on parasite species richness. These rodents appear to reflect a more complex pattern of parasite species richness, probably because of their close association with humans. Host specificity of parasites significantly decreases on islands, with the exception of Rattus rattus . We use parasitological data in order to explore the geographical connections between host populations. We show that parasites may help to resolve these connections but we emphasise that parasites are better geographic than phylogenetic markers.