The vocal repertoire of infant giant pandas (Ailuropoda melanoleuca)

Abstract

Infant giant pandas (Ailuropoda melanoleuca) are highly vocal during the first few weeks of their life. Despite this, no previous studies have attempted to systematically categorize infant giant panda vocalizations into different call types. In this study, we used acoustic and video analyses to split infant giant panda vocalizations into three distinct call types based on their acoustic structure as well as their use in different behavioural contexts. A discriminant functions analysis on the acoustic variables confirmed our initial subjective classification of 281 vocalizations into three call types: the harsh sounding “squawk”, the high-pitched “squall” and the pulsed “croak”. Based on the observed spectral acoustic characteristics, none of these three infant call types appears to be a precursor of an adult giant panda vocalization. In addition, individual call types could not be assigned to specific recording contexts. These findings suggest that infant giant panda vocalizations convey information about a cub's distress and need, rather than being tied to specific contexts of emission. Our objective demonstration that infant giant pandas have three basic call types provides a foundation for future studies of vocal ontogeny in this highly endangered species.

Keywords::

• Ailuropoda melanoleuca
• acoustic communication
• infant
• giant panda
• vocal repertoire

Acknowledgements

The authors thank the China Wildlife Conservation Association for its support and cooperation, and the China Conservation and Research Centre for the Giant Panda for giving Anton Baotic free access to record cubs at the nursery. The authors further thank Dr. Dagmar Schratter, Mag. Regina Pfistermueller and Mag. Herwig Pucher from Vienna Zoo for facilitating the research, and the editor and two anonymous reviewers for their constructive comments and recommendations for improving the manuscript. This research project was financially supported by the Austrian Federal Ministry of Education and Science. A. Stoeger was supported by the FWF Austrian Science Fund (No. P2309921), and B. Charlton was supported by a Leverhulme Trust Early Career Fellowship.

Notes

^1. Joint first authors.