Contextual and combinatorial structure in sperm whale vocalisations.

Sperm whales (Physeter macrocephalus) are highly social mammals that communicate using sequences of clicks called codas. While a subset of codas have been shown to encode information about caller identity, almost everything else about the sperm whale communication system, including its structure and...

Full description

Bibliographic Details
Published in:Nature Communications
Main Authors: Sharma, Pratyusha, Gero, Shane, Payne, Roger, Gruber, David F, Rus, Daniela, Torralba, Antonio, Andreas, Jacob
Format: Article in Journal/Newspaper
Language:English
Published: Nature Publishing Group 2024
Subjects:
Online Access:https://doi.org/10.1038/s41467-024-47221-8
https://pubmed.ncbi.nlm.nih.gov/38714699
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11076547/
Description
Summary:Sperm whales (Physeter macrocephalus) are highly social mammals that communicate using sequences of clicks called codas. While a subset of codas have been shown to encode information about caller identity, almost everything else about the sperm whale communication system, including its structure and information-carrying capacity, remains unknown. We show that codas exhibit contextual and combinatorial structure. First, we report previously undescribed features of codas that are sensitive to the conversational context in which they occur, and systematically controlled and imitated across whales. We call these rubato and ornamentation. Second, we show that codas form a combinatorial coding system in which rubato and ornamentation combine with two context-independent features we call rhythm and tempo to produce a large inventory of distinguishable codas. Sperm whale vocalisations are more expressive and structured than previously believed, and built from a repertoire comprising nearly an order of magnitude more distinguishable codas. These results show context-sensitive and combinatorial vocalisation can appear in organisms with divergent evolutionary lineage and vocal apparatus.