Landscape Ecology of the Long-Tailed Vole (Microtus Longicaudus) in Southeastern Arizona

Abstract

The way that animals interact with and use the landscape helps to form the foundation of ecological knowledge of a species. An individual’s home range is determined by a complex combination of interactions with the environment and conspecifics. Isolated populations that exist on the edge of a species’ distribution often exhibit adaptations to the extremes experienced by a species. Resources that an individual selects, contrasted against what is available, can provide valuable information regarding species-specific behavior and ecological relationships. Small mammals represent excellent study organisms to assess such relationships. We deployed radio transmitters on a peripheral population of the long-tailed vole (Microtus longicaudus) during the 2019 mating season in the Pinaleño Mountains of Arizona. We determined the core area, home range size, and interindividual overlap. We found that home range sizes are three to four times smaller than in other portions of the species’ range. We also found that females shared small portions of their home range with members of either sex, whereas males did not overlap other males but shared much of their home range with females. We evaluated resource selection at multiple scales using logistic regression. We found that voles generally selected for areas close to water and roads with high understory vegetation primarily composed of grasses. Resource selection varied between sexes suggesting different seasonal resource needs. Home range overlap and resource selection are consistent with species that display promiscuous and polygynous mating systems. Our home range study of this population provides valuable data, helping form a baseline for the southern edge of long-tailed vole distribution.