The effect of mammalian predator scent on the foraging behavior of Dipodomys merriami

Previous work has shown that kangaroo rats (Dipodomys) adjust foraging behavior to perceived risks of predation assessed via visual and auditory cues. A field study was performed in the Mojave Desert to determine if D. merriami also assesses predation risk via olfaction. The presence of mammalian predator urine was manipulated at food patches in two microhabitats (open and under shrubs) during two seasons and giving-up densities (GUDs) were measured to quantify D. merriami's foraging behavior. In winter, D. merriami exhibited a preference for feeding under shrubs but the presence of predator scent in the shrub microhabitat significantly reduced foraging activity. In summer, D. merriami again exhibited a strong preference for the shrub microhabitat but no effect of predator scent was observed. These results indicate that predator scent can affect kangaroo rat behavior suggesting that olfaction is used by kangaroo rats to assess predation risk. The results thus provide a more complete description of how predators affect the foraging behavior of desert rodents.