The Acoustic Properties of Low Intensity Vocalizations Match Hearing Sensitivity in the Webbed-Toed Gecko, Gekko subpalmatus

Abstract

The design of acoustic signals and hearing sensitivity in socially communicating species would normally be expected to closely match in order to minimize signal degradation and attenuation during signal propagation. Nevertheless, other factors such as sensory biases as well as morphological and physiological constraints may affect strict correspondence between signal features and hearing sensitivity. Thus study of the relationships between sender and receiver characteristics in species utilizing acoustic communication can provide information about how acoustic communication systems evolve. The genus Gekko includes species emitting high-amplitude vocalizations for long-range communication (loud callers) as well as species producing only low-amplitude vocalizations when in close contact with conspecifics (quiet callers) which have rarely been investigated. In order to investigate relationships between auditory physiology and the frequency characteristics of acoustic signals in a quiet caller, Gekko subpalmatus we measured the subjects’ vocal signal characteristics as well as auditory brainstem responses (ABRs) to assess auditory sensitivity. The results show that G. subpalmatus males emit low amplitude calls when encountering females, ranging in dominant frequency from 2.47 to 4.17 kHz with an average at 3.35 kHz. The auditory range with highest sensitivity closely matches the dominant frequency of the vocalizations. This correspondence is consistent with the notion that quiet and loud calling species are under similar selection pressures for matching auditory sensitivity with spectral characteristics of vocalizations.

Asymmetric Response to Heterotypic Distress Calls in the Lizard Liolaemus chiliensis

“…; Chen et al. ), and specifically to the fundamental frequency (Teichroeb et al. ; Lingle & Riede ).…”

“…The final hypothesis is that there is a matching between call characteristics and hearing sensitivities, and populations are tuned to the acoustic characteristics of their own distress calls (Manley et al 2014;Chen et al 2016), and specifically to the fundamental frequency (Teichroeb et al 2013;Lingle & Riede 2014). Teichroeb et al (2013) found a positive relation between the mean and the range of fundamental frequencies of mammalian distress calls.…”

Effect of the Level of Anesthesia on the Auditory Brainstem Response in the Emei Music Frog (Babina daunchina)

“…The temperature of the chamber was maintained at 23 ± 1°C. The stimulus presentations, ABR acquisition, equipment control, and data management have been described previously [28, 31]. For each subject three 27 gauge stainless steel electrodes (Rochester Electro-Medical, Inc. FL, USA) were inserted subdermally, at the midline above the medulla (about 3 cm caudal to the snout), above the tympanum and in the ipsilateral front leg as inverting, noninverting and ground electrodes, respectively.…”

“…ABR thresholds and latencies were determined using methods described in previous studies [28, 31]. Threshold measurements were defined as the lowest stimulus level for which no responses could be recognized by two experienced observers independently by visual inspection.…”

Chemical blindness in Liolaemus lizards is counterbalanced by visual signals, the case of two species with different communication modalities

“…Inter-individual interactions have led to the development of complex and dynamic communication systems, including the interaction of different sensory modalities in a multimodal communication model (Partan and Marler, 2005;Bro-Jørgensen, 2010). Lizards, in particular, tend to rely principally on chemical (Mason and Parker, 2010) and visual communication (Ord, Blumstein and Evans, 2002), although acoustic communication may also be present (Chen et al, 2016;Labra, Reyes-Olivares and Weymann, 2016). The interaction between chemical and visual modalities was studied in Sceloporus virgatus (males without ventral colour patches) and Urosaurus ornatus (males possessing ventral colourful patches) lizards (Hews and Benard, 2001), and results show that both species have developed different evolutionary strategies for communication, as each species relies differently upon the chemical or visual modality.…”