Written by Dr Helen Morrogh-Bernard (BNF UK Co-Director)
The Borneo Nature Foundation has recently published new research findings into the secret lives of orangutans in the Sebangau National Park peat-swamp forest. After six years of data collection and painstaking video playback and analyses, we’re proud to have published a paper on gestural communication in the International Journal of Primatology, titled: Gesture Use in Communication between Mothers and Offspring in Wild Orang-Utans (Pongo pygmaeus wurmbii) from the Sebangau Peat-Swamp Forest, Borneo. You can access the full article here.
This paper explores how orangutans use non-verbal signals to communicate and is the first in-depth study of its kind in the wild. Gestural communication usually involves hand signals, pointing, movement of eyes and face, otherwise known as body language, which humans may take for granted, but we are beginning to learn that wild orangutans have similar ways of communicating.
Orangutans are the most solitary of all apes so documenting interactions between individuals takes time. For this project, we concentrated on our seven resident females and their offspring in Sebangau as mother-offspring pairs are the most stable social grouping. During the long period of field research, we saw the offspring grow and develop, and we saw how they learned to communicate.
Together with Exeter University students Andrea Knox and Emma How, and great ape gesture expert Dr Catherine Hobaiter, we identified 21 unique gestures and 11 vocal calls. Although studies of orangutans in captivity found more gestures overall, we identified three new gestures, emphasising how important wild studies are, even if they are more time-consuming and difficult!
This project has been a truly collaborative effort between BNF, CIMTROP at the University of Palangka Raya, the University of Exeter and the University of St Andrews, and we thank Abdul Aziz, Joey Markx and the rest of the field team who spent three years collecting over 600 hours of video footage of possible gestures. This is extremely hard work, time-consuming and takes great dedication and patience – and strong neck muscles – on the part of the person filming!
The Sebangau orangutans have given us a glimpse into their secret world of communication, but we think there are many more gestures still to be discovered, and this study on orangutan gestures in their natural environment may be just the tip of the iceberg.