Yellow-bellied marmots discriminate between the alarm calls of individuals and are more responsive to calls from juveniles

Unlike individually distinctive territorial calls, contact calls, or calls that aid in the recognition of young by their parents, the function or functions of individually distinctive alarm calls (vocalizations produced in response to predators) is not immediately apparent. Yellow-bellied marmots, Marmota flaviventris, ground-dwelling sciurid rodents, produce individually distinctive alarm calls. Using an habituation-recovery playback protocol, we show that marmots can perceive differences between the calls of different adult females. We further show that marmots are able to discriminate between at least one broad age-sex category. In contrast to what has been reported in other species, playback of calls from juveniles elicited a greater response (i.e. marmots increased vigilance and suppressed foraging) than did playback of calls from adult females. No other age-sex category led to responses significantly different from adult females. Future studies will seek to understand why individual discriminative abilities exist, but we have shown that individuals are able to identify when young, and presumably vulnerable, marmots are calling, and to respond by engaging in vigilance. (C) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.