Аннотация:Investigation of bat vocalization in winter was conducted in abandoned mines of
the Middle Volga. We wakened up the animals by a light touch and recorded their
sounds using portable recorder Sony TC-D5M. In total, 473 phonograms of seven bat
species were analyzed. The series of sounds consisted of 3–22 signals of mean duration 1.24±0.58 s with mean interval 1.35±0.70 s between them. As a rule, the signals
included as the constant frequency, as well as frequency modulated harmonic components. In addition, many calls showed so-called non-linear phenomena: determinated
chaos, sub-harmonics, biphonations, sidebands, frequency jumps. Based on the duration of such non-linear portions, we cleared up that the sounds of awakening bats
had been well differed between the species (Table 1). Moreover, within the each
species there were significant differences revealed between calls of males and
females (Table 2).