P. rubicunda is almost wholly arboreal, having a clear preference for primary forest. This colobine species’ annual diet is mostly comprised of folivory on young leaves (36%), seed eating (30%), and combined frugivory on pulpy, seedy fruits and florivory (34%). This diet varies throughout the year as availability of food sources shifts (Davies 1991). In Sabah, a group ofP. rubicunda was found to rely on lianas for about 32% of their total diet; the rest were tree species. Overall, the group exploited over 102 plant species over a single year (Davies 1984). It is also found in swamp forests (Chivers and Burton 1988), and evergreen forests (Bennett and Davies 1994). It occasionally visits native gardens in search of food (Yanuar et al. 1993). It is found in primary and secondary lowland forests, not above 2,000 m, and is able to tolerate forests that have regenerated after logging has taken place (Payne et al. 1985).