QUANTIFYING PREDATION RISK FOR REFUGING ANIMALS - A CASE-STUDY WITH GOLDEN MARMOTS

Although a variety of behaviors expose animals to some risk of predati on, there is no accepted way to compare their relative risk. For anima ls that retreat to refugia when alarmed by predators, the proportion o f time devoted to each out-of-refuge behavior multiplied by the total time required to return to a refuge can be used to compare a behavior' s relative predation risk. Total time to return to a refuge is a funct ion of both response time - the time required to respond to an increas ed risk of predation-and travel time-the time required to flee to a re fuge once alarmed. Quantifying these components can illustrate how ani mals minimize exposure to predators. Golden marmots (Marmota caudata a urea) were a refuging prey species used to examine the utility of this measure and to understand how marmots minimized their risk of exposur e to predation. Golden marmots devoted different amounts of time to lo oking, foraging, self-grooming, and playing. To estimate the behavior- specific time required to return to refugia, the location of different activities was noted and a behavior-specific travel time was calculat ed. Alarm calls were played back to marmots engaged in different behav iors to determine, in a standardized manner, if there were behavior-sp ecific response times. Marmots appeared to minimize their predation ri sk by performing most behaviors close to refugia. Results suggest that foraging was the riskiest behavior, largely because marmots foraged f ar from refugia and spent about 30% of their time foraging. While samp le sizes were small, results also suggested that play, a rare adult be havior, exposed animals to predation because of a relatively long resp onse time.