Vocal communication in the striped field mouse, Apodemus agrarius, in dyadic encounters and intraspecific cage groups.

The aim of this research was to describe and analyse the vocal signals emitted by males and females of Apodemus agrarius in dyadic encounters and intraspecific cage groups. Most of the sounds recorded were in the context of agonistic behaviour. The sounds were classified into three main groups: The first group corresponded to calls with clear harmonic structure. They varied in frequency, duration and intensity. During attacks and fights, the calls were louder and with a higher dominant frequency (8.7±0.2 kHz) than those produced in response to opponent approach (4.4±0.07 kHz). The second group included relatively short harsh calls - with noise component but without clear harmonic structure. The third group of vocalizations corresponded to the calls resembling low clucks. They were characterized by a low dominant frequency, 1.0±0.01 kHz, and brief duration. The context and possible functions of the described calls are discussed. [ABSTRACT FROM AUTHOR]