The odors of predators influence the behavior of the silky pocket mouse, Perognathus flavus (Rodentia)

Abstract

Studies were conducted to assess the behavioral responses of silky pocket mice, Perognathus flavus, to test odors associated with two naturally occurring predators (northern grasshopper mouse, Onychomys leucogaster, and Norway rat, Rattus norvegicus), a novel test odor (sugar glider, Petaurus breviceps), and a control odor (water). Pocket mice were tested in a chamber in which they had access to two cages containing food; one of these cages contained no odor (control), while the other contained a predator odor. When both cages contained no test odors, pocket mice showed no preference for one cage over the other; they spent equivalent amounts of time in and in front of each cage, and in the frequency of feeding bouts within cages. In contrast, P. flavus avoided odors associated with grasshopper mice and Norway rats. They entered cages containing predator odors far less frequently than the control cages, exhibited significantly reduced exploratory activity, and took significantly smaller amounts of food. Pocket mice entered cages containing odors associated with a non-predator (novel odor, sugar glider) more frequently than cages containing odors associated with grasshopper mice. Because all test subjects had no prior experience with grasshopper mice or Norway rats, these results suggest that P. flavus has an innate ability to detect and respond to odors associated with these two predators.