We examined intraspecific space use of free-ranging kangaroo rats (Dipodomys heermanni) during the breeding season using behavioral observations and radiotelemetry. Home ranges of males were significantly larger than those of females. Female D. heermanni maintained exclusive territories with essentially nonoverlapping home ranges, whereas home ranges of males overlapped with both same- and opposite-sex conspecifics, reflecting the different strategies of the different sexes. This follows a general pattern found in mammals in which spacing reflects limiting resources. There was, however, high individual variation in home range size for males, which may suggest a role for social interactions in determining spatial behavior in this species. D. heermanni, a medium-size species, appears intermediate in space use compared with the larger D. spectabilis and the smaller D. merriami.