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Christian, D.P. 1982. Habitat requirements and habitat restriction of Microtus chrotorrhinus in northeastern Minnesota. Final report submitted to the Nongame Wildlife Program, Minnesota Department of Natural Resources. 36 pp.


The rock vole typically has a very "patchy", discontinuous distribution. Our knowledge about the specific habitat and microhabitat requirements of rock voles, particularly Microtus Chrotorrhinus, is at best incomplete. The purpose of this study is to increase knowledge of the microhabitat and specific habitat of the rock vole. We did this by using mark-release-recapture live-trapping methods. Physical and vegetative characteristics of all trapping sites were also measured. Results indicate that rock voles, at least at this study site, are much greater specialists relative to physical habitat structure, and as a result are more restricted spatially than two other species, C. gapperi and P. maniculatus. Thus data in this study suggest that 1) as a result of microhabitat specialization, many qualitatively suitable habitats for rock voles in northeastern Minnesota may be quite small and 2) consequently, many populations of this species in the state may be small, extremely localized, and spatially restricted. Results suggest that the abundance of rocky microhabitats with reasonably dense ground and shrub vegetation may be needed to support rock voles at high density. Further work on rock voles is needed to both determine microdistributional patterns and to monitor long-term stability of these potentially vulnerable populations.