Alarm Calling in Plateau Pika (Ochotona curzoniae): Evidence from Field Observations and Simulated Predator and Playback Experiments

SIMPLE SUMMARY: With the continuous progress in research technology, it is found that auditory signals are particularly important for social rodents. The plateau pika (Ochotona curzoniae) is a type of rodent with song characteristics. The study of the biological meaning of its song can provide a theoretical basis for understanding the adaptive evolution of the communication methods of burrowing rodents. So far, the acoustic signal and behavioral response analysis of the plateau pika have been carried out independently, and there is no comprehensive understanding of the biological significance of the calls of the plateau pika. In this study, based on previous studies on the call of plateau pikas, it is assumed that plateau pikas can use acoustic signals to transmit alert information. To test this, we first collected the alarm call of plateau pikas, and then used field playback experiments to verify the alarm call of plateau pikas. Finally, in order to determine the universality of the alarm call of plateau pikas, we conducted playback experiments in different regions. Our research results show that plateau pikas can transmit alert information through acoustic signals, and their alert calls are responded to differently in different regions. ABSTRACT: Acoustic communication plays a vital role in passing or sharing information between individuals. Identifying the biological meaning of vocal signals is crucial in understanding the survival strategies of animals. However, there are many challenges in identifying the true meaning of such signals. The plateau pika (Ochotona curzoniae) is a call-producing mammal endemic to the Qinghai–Tibet plateau (QTP) and considered a keystone species owing to its multiple benefits in alpine rangeland ecosystems. Previous studies have shown that plateau pikas emit alarm calls as part of their daily activities. However, only field observations have been used to identify these alarm calls of the plateau pika, with no attempts at using playback experiments. Here, we report the alarm calling of plateau pikas through field observations as well as simulated predator and playback experiments in the Eastern QTP from 2021 to 2022. We found that both female and male adults emitted alarm calls, the signals of which comprised only one syllable, with a duration of 0.1–0.3 s. There were no differences in the characteristics between the observed alarm calls and those made in response to the simulated predator. The duration of the alarm call response varied with altitude, with plateau pikas living at higher altitudes responding at shorter durations than those at lower altitudes.