Sound analysis of social calls in chinchillas

J. Bartl¹, M. Schneider¹, H.U. Kleindienst² and M. Erhard¹

¹Institute of Animal Welfare, Ethology, and Animal Hygiene, Ludwig-Maximilians-University, Munich, Germany
²Max-Planck-Institute for Ornithology, Seewiesen, Germany

Chinchillas are sociable rodents living in families. It is well known that chinchillas have a hearing range very close to that of humans (125 Hz-16 kHz) and have many different kinds of vocalizations at their disposal.

The aim of this study was to get a survey of vocal behavior of chinchillas living in sociable groups. During one year twenty chinchillas, housed in aviaries in 8 groups of 2 to 6, have been investigated.

Vocalizations of the chinchillas were recorded on magnetic tape with a 4 DS Racal Recorder with frequency response of 100 Hz to 19 kHz. All vocalizations were digitalized with Avisoft SasLabPro software program (16 bits, sampling frequency 22050Hz) and spectro- and sonagrams were made. Syllables were sonographically analyzed and classi.ed according to parameters like frequency, intensity, duration and number of harmonics. After that the arrangement of syllables to entire calls was examined. While chinchillas were active their behavior was directly observed.

At this stage 10 call types, based on different physical structure have been distinguished and associated with three different functional categories. Three call types occurred during defensive aggressive interactions between family members, two during offensive aggressive interactions, and two further calls during friendly contact between adult chinchillas and one other call between adults and young. In addition, one call could be associated with sexual behavior and another one with prevention of raptors (alarm call).

Because of individual differences in the call variations, the sometimes smooth transition between some syllables and the variety of combinations only ten different vocalizations could be connected with a specific context.

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.

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