Studying functional performance in rodents can help us understand how they use their habitat. For example, studying bite force might help us understand their feeding ecology. Similarly, studying grasping force might help us understand their climbing abilities. However, not much is understood regarding how biting and grasping forces vary among species that occupy the same habitat. We measured grasping and biting forces of four different species found in the Suisun Marsh, including the endangered salt marsh harvest mouse (Reithrodontomys raviventris halicoetes), western harvest mouse (Reithrodontomys megalotis), California vole (Microtus californicus), and house mouse (Mus musculus) using a force transducer. In addition, we measured the relative sizes of the forefeet and rostrum of each individual to explore anatomical correlates of these forces. According to our preliminary results, peak grasping and biting forces (scaled to body size) were greatest in the California vole, followed by the western harvest mouse, salt marsh harvest mouse, and house mouse. This pattern could reflect differences in foraging and/or locomotion, such as the voles’ tendency to burrow and the house mouse’s generalized behavior. Further morphological analyses suggest that manus surface area is positively correlated with grasping force, but rostrum length does not explain variation in bite force among individuals. These results help pinpoint key aspects of morphology that might be correlated to differences in feeding behavior and microhabitat use among species.