Reyes-Olivares, C., D. Charlin, M. Penna & A. Labra

Acoustic, visual, and chemical social behaviours of the Chilean Marked Gecko (Garthia gaudichaudii). pp. 168-182 plus Supplementary audio file, Supplementary video 1, Supplementary video 2, Supplementary video 3, Supplementary video 4, Supplementary video 5, Supplementary video 6, Supplementary video 7.

Abstract. Geckos stand out among lizards for communicating by means of visual, chemical, and acoustic modalities. Although these lizards are known for using these three modalities, the number of studies using them as subjects is restricted, especially those focused on the Chilean endemic genus Garthia. Here, we quantify the social behaviour of G. gaudichaudii, with special focus on the acoustic component. We also examine behaviours linked to the use of visual and chemoreceptive signals, and how these relate to acoustic signals, shedding light on the potential use of multichannel communication in this species. We examined social interactions of these lizards during encounters between pairs of non-breeding adult individuals of same or different sex. We found that both sexes emit single chirp calls of low intensity and at a low rate. Females calls preceded the approach of an interacting individual (male or female), while a single male called exclusively while ramming a female. We suggest an intimidatory functional role for these calls. Geckos also performed different visual displays, among which aggressive vertical tail-waving is followed by aggressive single chirp calls. Both sexes performed tongue-flicks, mainly to the air or to a conspecific, suggesting that vomerolfaction of volatile and non-volatile chemicals is important for chemical communication in this species. Some males performed courtship behaviours, but no copulation was recorded. Females rejected males performing tail-waving displays and made escape attempts, likely because experiments involved non-breeding subjects. Our study demonstrated that female and male G. gaudichaudii use acoustic signals coupled to various visual and chemoreceptive behaviours during social interactions.

Key words. Reptilia, Squamata, aggressive interactions, lizards, multisensory communication, single chirp call, tail-waving, tongue-flick.