IVth International Conference on Dormice (Rodentia, Gliridae)13 - 16 September 1999 EDÝRNE - TURKEY |
VOCALIZATION OF THE JAPANESE DORMOUSE, GLIRULUS JAPONICUS =REPERTOIRE AND DEVELOPMENT OF VOCALIZATION IN THE YOUNG=
Minato, S. * & Hidaka, T.**
*434 Kaminagai, Kumanogawa, Wakayama, 647-1201, Japan, e-mail: yamane@ripnet.or.jp
** University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga,522-8533, Japan
This study was performed in the framework of research of reproduction and vocal communication in the Japanese dormouse, Glirulus japonicus, to follow and describe the repertoire and development of vocalization in the young.
Their vocalization was categorized into 6 types.
1) Drift-calls: From day 0 drift-calls were frequent and decreased to zero when the eyes opened. In many cases their frequency range fell into the ultrasonic region with some harmonics, and the duration was short. They are considered to induce protective activities of the mother.
2) Kyu-kyu calls: The frequency range was narrow and was found in the audible region, and the duration was long. They appeared almost simultaneously with eye opening.
3) Clicks: The duration was quite short. They were subdivided into two types based on their frequency range (low- and high- range).
4) Twitters: Twitters consisted of repeated clicks at low frequencies in a narrow range.
5) Churu-churu calls: These calls had a wide frequency range with some modulation.
Comparison of the vocalization of the young of Glirulus japonicus, Dryomys nitedula and Muscardinus avellanarius showed that they were quite different and had specific characteristics.