Abstract and Summary

Two populations of individually marked pikas (Ochotona princeps) were studied on Niwot Ridge, Boulder County, Colorado, U.S.A., to determine if these lagomorphs are able to, and actually do, recognize other individuals through the use of vocal cues contained in the short call. Discriminant function analysis demonstrated that short calls are individually distinct in structure. Furthermore, pikas responded differentially to naturally occurring calls from different individuals and recognition appears to be possible solely through the use of vocal cues contained within the short call.

Pikas also discriminated between playbacks of familiar and unfamiliar short calls. The strength of response appears related to the level of competition and the relative amount of threat that a familiar or unfamiliar pika represents to the responding individual.