Are gastrointestinal parasites associated with the cyclic population dynamics of their arctic lemming hosts

摘要: Abstract Many rodents, including most populations of arctic lemmings (genus Dicrostonyx and Lemmus), have cyclic population dynamics. Among the numerous hypotheses which been proposed tested to explain this typical characteristic some terrestrial vertebrate communities, trophic interactions often presented as likely drivers these periodic fluctuations. The possible role parasites has, however, only seldom assessed. In study, we genetically measured prevalence two endoparasite taxa, eimerians cestodes, in 372 faecal samples from collared lemmings, over a five year period across three distant sites Northeast Greenland. Prevalence cestodes was low (2.7% all years) taxon found at one site (although 4 out 5 adult hosts. By contrast, high for (77.7% years), occurred sites, every year, both age classes (at Hochstetter Forland where juvenile faeces were collected) regardless reproductive social status inferred characteristics lemming nests had collected. significantly varied among years (not sites) higher than site. However, (Pt) associated with lower density (Nt) no delayed dependence between Nt Pt+1 support parasite hypothesis. Our results show that there is clear relation eimerian Greenland hence evidence could be driving dynamics region.