the ecological niche of a parasite exists only at the nexus of certain abiotic and biotic conditions suitable for both the definitive and intermediate hosts. however, the life cycles of most parasites are not known, or are poorly known, and using known ranges of hosts to find endemic parasitic infections has been difficult. however, with ecological niche modeling, we can create potential range maps using known localities of infection. testing the validity of such maps requires knowledge of the localities of other parasites with common history. here, we find that the ecological niche of a tapeworm parasite of voles, paranoplocephala macrocephala (cestoda: anoplocephalidae), allows prediction of the presence (in ecological and geographic space) of 19 related parasite species from 3 genera in 23 different hosts throughout the nearctic. these results give credence to the idea that this group shares similar life cycle requirements despite phylogenetic distance. this work further validates ecological niche modeling as a means by which to predict occurrence of parasites when not all facets of the life cycle are confirmed. such inductive methods create the opportunity for deducing potential reservoir or intermediate hosts, and complementing studies of parasite biodiversity and community ecology.