Male Carollia perspicillata bats call more than females in a distressful context

Abstract

Distress calls are a vocalization type widespread across the animal kingdom, emitted when the animals are under duress, e.g. when captured by a predator. Here, we report on an observation we came across serendipitously while recording distress calls from the bat species Carollia perspicillata , i.e. the existence of sex difference in the distress calling behaviour of this species. We show that in C. perspicillata bats, males are more likely to produce distress vocalizations than females when hand-held. Male bats call more, their calls are louder, harsher (faster amplitude modulated) and cover lower carrier frequencies than female vocalizations. We discuss our results within a framework of potential hormonal, neurobiological and behavioural differences that could explain our findings, and open multiple paths to continue the study of sex-related differences in vocal behaviour in bats.

Amplitude modulation pattern of rat distress vocalisations during fear conditioning

“…Amplitude modulations in human screams have been proposed as the correlate of acoustic roughness (Arnal et al, 2015). In bat distress calls (González-Palomares et al, 2021; Hechavarría et al, 2020), fast amplitude modulations occur in ~48 % of the cases at rates ~1.7 kHz, also have been suggested to express a higher degree of urgency. We investigated here if amplitude modulations occur in rat vocalisations.…”

“…A study in passive listening mice reported that, in contrast to humans, mice seemed to perceive dissonant sounds (two tones played simultaneously with high roughness levels) more pleasant than consonant sounds (Postal et al, 2020). In bats, fast-AM between 1.15 and 2.45 kHz have been described in 48 % of the distress calls studied (González-Palomares et al, 2021; Hechavarría et al, 2020). Bats distress vocalisations characterised by fast-AM enhances the activity in the hypothalamic-pituitary-adrenal axis (Mariappan et al, 2013) and the dopaminergic system (Mariappan et al, 2016), hence suggesting that fast-AMs could be a correlate for roughness perception in bats.…”

Amplitude modulation pattern of rat distress vocalisations during fear conditioning

“…Though rat vocalisations have been investigated extensively, at present, it remains unknown whether they carry amplitude modulations (AMs). AMs occur in fearful vocalisations of other species, such as human screams 16 and bat distress calls 17 , 18 . One hypothesis that has been put forward in recent years is that AMs represent an acoustic correlate of perceptual roughness across species 16 , 17 , 19 .…”

Deviance detection in subthalamic neural population responses to natural stimuli in bats

“…Like all echolocating bats, Carollia perspicillata navigates in the dark by emitting stereotypical acoustic pulses and listening to the echoes reflected off objects in its environment. In addition, this bat species has a large variety of social communication calls [1,2], which is a consequence of its social lifestyle, with groups of more than 100 individuals sharing the same roost [3]. This has led to the development of a broad variety of social communication calls.…”