Our flagship Orangutan Behaviour Project has been ongoing since 2003, following wild orangutans (Pongo pygmaeus wurmbii) in their natural habitat. We know and study 40 individuals, with the long-term objective of understanding orangutan behaviour and ecology in tropical peat-swamp forest habitat, and the impacts of human activities on the species. Special focus is given to: (i) feeding behaviour, energetics and health; and (ii) social networks, relatedness, communication and dispersal. This research is vital for understanding how human activities can endanger, and conserve, this threatened species. It’s tough work following orangutans in the flooded and dense peat-swamp forest, but we were rewarded in 2010 with the birth of a new baby boy orangutan, Fio, to his mother Feb, our most followed and best-known individual. We started following her when she was just leaving her own mother in 2003, so to see her give birth to her first baby was very exciting for us all!

Gibbons are harder to study than orangutans because they travel very quickly through the canopy and are difficult to habituate. We are therefore very proud of our Gibbon Behaviour Project, which is one of very few long-term studies of these primates in the world. Ours are southern Bornean gibbons (Hylobates albibarbis), and we monitor their population size, distribution, social behaviour, diet, development and health; study how energy intake is governed by food availability; investigate singing behaviour and effects of changing climatic conditions on this; investigate the effects of anthropogenic disturbance and conservation measures on the gibbon population; and compare gibbon behaviour, diet and nutrient intake with that of the sympatric orangutans and red langurs. To date the project has collected over 3,000 hours of focal-animal follow data on 27 individuals.

Population density surveys have been completed in Sabangau, indicating that our forest is home to a vital red langur population. Eight groups of langurs have been identified within the research area at the Setia Alam Field Station and three are followed regularly, facilitating data collection of behavioural, ranging and feeding ecology, including over 100 food items from over 80 tree and liana species during more than 800 follow hours. Data are now being analysed to establish home-range size and degree of overlap, and a collaborative study between primate research projects is being developed to investigate resource use, niche separation and competition.