Dr. Merav Ben-David


Body mass, which represents the energy demands of animals, has been identified as an important predictor of home range size in many terrestrial and marine mammals. In most studies, only interspecific effects of body size have been explored but few addressed the effects of sexual dimorphism within species. Female-biased sexual size dimorphism is typical in most chipmunk species, including the least chipmunk (Tamias minimus). In September 2015, we radio collared 23 chipmunks (14 males and 9 females) in two forest and two sagebrush grids and tracked them daily. Tracking lasted from 5-31 days. Using kernel density estimators of repeated relocations we found that despite differences in body mass, male and female home ranges were similar in size. Similarly there was no sex-related difference in maximum daily distance moved. There was little 2 of 27 overlap of home ranges at the 50% contour among all chipmunks, but while females showed little overlap with other females at the 95% contours, there was substantial overlap between males and females as well as males and males. We also found that several pairs of chipmunks which exhibited high overlap in home range shared hibernacula, and many sagebrush chipmunks established hibernacula in forested stands. Our results suggest that body size had no effect on space use of chipmunks and that while females may be territorial, males are not. Relatedness among individuals that exhibit home range overlap and those that share hibernacula should be investigated in future studies.


Zoology and Physiology

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