Journal of Ethology

, Volume 31, Issue 2, pp 115–121 | Cite as

Alarm call discrimination in a social rodent: adult but not juvenile degu calls induce high vigilance

  • Ryo Nakano
  • Ryoko Nakagawa
  • Naoko Tokimoto
  • Kazuo OkanoyaEmail author


Many social animals develop vocal communications to send and receive information efficiently in a group. In alarm communication, call recipients in a social group evaluate alarm calls, enhancing their probability of survival in the face of predatory threats. Calls from naïve and younger group members might be less evocative, in terms of rendering group members vigilant, than calls from more experienced adults because adults are generally more reliable. It remains uncertain, however, what acoustic characteristics render an alarm call reliable. Here, we report that adult degus, Octodon degus (Rodentia, Octodontidae), produced an alarm with a frequency-modulated (FM) syllable, accompanied by low bandwidth and entropy, to evoke a high-vigilance response amongst receivers. Unlike adults, subadult degus did not emit the FM syllable in the warning context, and their call without the FM syllable evoked less vigilance than the adult alarm. We suggest that the FM structure of the adult-produced syllable serves as the primary feature characterizing a reliable alarm call. Our results are consistent with those found in other social rodents, e.g., ground squirrels and gerbils, also produce FM alarm calls in high-urgency situations supports the importance of the FM syllable in alarm communication.


Acoustic communication Alarm call Cognition Frequency modulation Predator Social behavior Vigilance 



We thank all of the staff of our laboratory for devoted care of the degus, and A. Greener, N. Hirasawa, M. Miyamoto and T. Miyamoto for recording the hawk call at the Fuji Kachoen. We are also grateful to J.F. Hare for providing constructive advice on an earlier version of the manuscript.

Supplementary material

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Copyright information

© Japan Ethological Society and Springer Japan 2012

Authors and Affiliations

  • Ryo Nakano
    • 1
    • 3
    • 4
  • Ryoko Nakagawa
    • 1
    • 2
    • 5
  • Naoko Tokimoto
    • 1
    • 6
  • Kazuo Okanoya
    • 1
    • 7
    Email author
  1. 1.Brain Science Institute, RIKENWakoJapan
  2. 2.Graduate School of Advanced Integration ScienceChiba University, Inage-kuChibaJapan
  3. 3.Breeding and Pest Management DivisionNARO Institute of Fruit Tree ScienceTsukubaJapan
  4. 4.Neurosensing and Bionavigation Research CenterDoshisha UniversityKyotanabeJapan
  5. 5.Graduate School of Biomedical SciencesHiroshima UniversityHiroshimaJapan
  6. 6.Faculty of Policy ManagementShobi UniversityKawagoeJapan
  7. 7.Department of Life Sciences, Graduate School of Arts and SciencesThe University of TokyoTokyoJapan

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