Foraging Behavior of Heteromyid Rodents: Field Evidence of Resource Partitioning

Nocturnal, above-ground movement patterns of three desert heteromyid rodents, Dipodomys merriami, Perognathus formosus, and Perognathus longimembris, were studied in a Mohave desert-scrub habitat. Dipodomys merriami moved long distances between stops, remained stationary for long periods of time and collected a low diversity of seeds when compared to the Perognathus. In contrast, both Perognathus moved short distances between stops, spent little time stationary, and collected a wide range of seed types. These differences are consistent with the hypothesis that Dipodomys forage for rich seed clumps, whereas Perognathus forage for more dispersed seed resources. That Dipodomys and Perognathus show differences in the diversity of seeds collected is additional evidence that intergeneric modes of foraging may differ. Differential foraging behaviors leading to the exploitation of seed resources may be one of the mechanisms which facilitates the coexistence of desert rodents.