Orang-utans (Pongo spp.) are primarily frugivorous (Morrogh-Bernard et al. 2009) and are often regarded as important seed dispersers (Corlett 1998). In Tanjung Puting, Borneo, Galdikas (1982) found intact seeds in 94% of faecal samples, with a median 111 seeds per defecation; and in Ketambe, Sumatra, Rijksen (1978) found seeds in 44% of faecal samples. Furthermore, orang-utans have large day ranges (e.g. mean = 968 m, range = 280–2834 m across adults in Sabangau; Harrison 2009) and slow passage rates of digesta through the gut (Caton et al. 1999), and, hence, may disperse seeds far from parent trees. Many seeds are also spat out or discarded at distances up to 75 m from parent trees (Galdikas 1982).
