Behavioral Relationships between Two Sympatric Voles (Microtus): Relevance to Habitat Segregation

This study was undertaken to examine the role of behavioral interactions in maintaining habitat segregation in sympatric populations of Microtus pennsylvanicus and Microtus montanus. In 145 staged encounters between pairs of mice, 79 interspecific and 66 intraspecific, M. pennsylvanicus displayed more agonistic behavior than did M. montanus and was usually dominant in interspecific interactions. These data, combined with examination of the habitats used by these voles where their ranges do not overlap, suggest that interspecific behavioral interactions may prevent M. montanus from invading mesic habitats occupied by M. pennsylvanicus.