Search

Echolocation calls emitted by the 4 species of Cuban mormoopid bats were compared to determine vocal signatures that enable identification of each species in the field during their evening exodus. Echolocation calls produced by Mormoops blainvilli are downward frequency-modulated (FM) signals in the range of 68.4– 52.5 kHz. Echolocation calls emitted by Pteronotus macleayii and P. quadridens have a similar design consisting of a short constant-frequency (CF) segment followed by a downward FM segment. The CF segment was at 70.0 kHz in calls from P. macleayii, and at 83.3 kHz in calls from P. quadridens. Echolocation calls from P. parnellii consist of a long CF segment, which is preceded by a short initial upward sweep and followed by a downward FM terminal sweep. The CF value of the 2nd harmonic was a good parameter for species identification. The features of the echolocation calls of each of the species were used to identify them during the evening exodus from 2 Cuban caves.

Echolocation calls were recorded from Pteronotus quadridens flying in the field and in an enclosed space. In the field, search calls contained 1 or 2 harmonics. Patterns of call design show a segment of quasi–constant frequency (QCF2nd-harmonic at 81–84 kHz), followed by a downward frequency-modulated (FM) component. The 2nd harmonic was always more intense than the 1st. Search, approach, and terminal phases of calls were described during hunting sequences of P. quadridens. The transition between call phases was characterized by monotonic variations in some acoustic parameters, including a decrease in call duration and an increase in repetition rate, bandwidth, and slope of the FM component. We also analyzed calls emitted by bats flying in confined spaces that consistently contained 3 harmonics, of which the 2nd harmonic contained the greatest energy. The values of call duration were shorter and bandwidth was higher than values characterizing calls emitted during the search phase in the field.