SMC conceived of the study and carried out the behaviour and ecological habitat analysis for this research.
SMC would like to thank Aurelién Brulé (Chanee), the director of the
Kalaweit Project, and all staff who helped with data collection. Also
to LIPI, the Indonesian Institute of Science for permission to work in
Kalimantan. Funding was provided by The Gibbon Foundation, the C.K.
Marr Educational Trust and Downing College, Cambridge.