Analisi acustica dei canti dei gibboni nel Huai Kha Khaeng Wildlife Sanctuary, Tailandia.

Università degli Studi di Torino Dipartimento di Scienze della Vita e Biologia dei Sistemi Evoluzione del Comportamento Animale e dell'Uomo RIASSUNTO Candidato/a: Giovanni Boris Di Panfilo Docente responsabile: Prof. Marco Gamba Titolo: Acoustic analysis of the gibbon song in the Huai Kha Khaeng Wildlife Sanctuary, Thailand. One of the most significant unanswered questions about human evolution deals with the rise of speech and music. Gibbons are the humans phylogenetically closest relatives showing the singing behavior. In white-handed gibbons (Hylobates lar), different kinds of songs were described: both sexes can emit solo songs, or the reproductive pair can produce a particularly coordinated duet. I collected audio recordings with the ad libitum method on four habituated male gibbons inhabiting the evergreen and dry forest surrounding Khao Nang Rum Wildlife Research Station in Huai Kha Khaeng Wildlife Sanctuary, during a six months fieldwork period, from March to August 2019. I identified 26878 vocalizations from 41 male songs, divided in solo songs and “hoo solo songs”; then, using the software PRAAT I extracted frequencies and temporal features. I analyzed the inter-onset intervals of two following notes within a phrase and between two subsequent phrases to understand the rhythmic structure of phrases and songs. I found that between- phrases inter onset intervals are significantly longer, but coefficient of variation did not differ significantly. By considering units of short, intermediate, and long duration, I have also found that median pitch and range of the fundamental frequency increased according to duration. Individual variation in these features could indicate the capability to recognize particular pitch patterns in non-human primates. Furthermore, the temporal dynamics of songs allow the understanding of the individual potential for timing and which could be the adaptive meaning of rhythm.