Scent marking by voles in response to predation risk: a field-laboratory validation

Predators use scent to locate their prey, and prey animals often alter their behavior in response to predation risk. I tested the hypothesis that voles would decrease their frequency of scent marking in response to predation risk. I conducted trials in which prairie voles, Microtus ochrogaster, and woodland voles, M. pinetorum, were allowed to scent mark ceramic tiles placed in their runways in the field. The tiles were subjected to one of three treatments: scented with odor from mink, Mustela vison (a rodent predator); rabbit, Oryctolagus cuniculus (a nonpredator mammal control); and no odor (control). No significant differences were found in the frequency of scent marking in response to the three treatments for either species. To validate that voles did not decrease their scent marking in response to predation risk, I brought male prairie voles from the field site into the laboratory and allowed them to scent mark white paper substrate treated with mink odor, rabbit odor, or no odor. No significant differences were found in the frequency of scent marks in response to the three treatments. These results differ from what was predicted based on laboratory studies with other species of rodents that show avoidance, reproductive suppression, decreased activity, and reduced scent marking in response to odors of predators. Voles appear to scent mark different substrates and under a wide variety of social and environmental situations, and this is not influenced by the presence of odor from a predator. Copyright 2004.