Effects of habitat fragmentation on meadow vole (Microtus pennsylvanicus) population dynamics in experiment landscape patches

This study examined the effects of habitat fragmentation on meadow vole (Microtus pennsylvanicus) population dynamics in experimental landscape patches. The study was conducted from May-November 1993 at the Miami University Ecology Research Center. Fight 0.1-ha small mammal enclosures were used. Four enclosures contained a 160 m(2) nonfragmented patch and four enclosures contained four 40 m(2) fragmented patches. Thus, each treatment was replicated 4 times in a systematic research design. The patches in both treatments contained high-quality habitat surrounded by low-quality matrix. Six pairs of adult meadow voles were released in each enclosure on 27 May 1993. Populations were monitored by live-trapping and radio-telemetry methods. Significantly greater densities of female voles were found during October in the fragmented treatment compared to the nonfragmented treatment. Also, significantly more females than males were found in the fragmented treatment compared to the nonfragmented treatment for the total study period. Significantly more subadult and juvenile males were found in the matrix versus the patch of the nonfragmented treatment compared to the fragmented treatment. Males in the fragmented treatment had significantly greater mean home range size than males or females in the nonfragmented treatment. There appears to exist a relationship between patch fragmentation and the social structure of meadow vole populations; this relationship appears to function as a population regulatory mechanism.