This is “William” one of a pair of North Borneo Gibbons Hylobates funereus that “own” the gibbon territory next to the Belalong Canopy Walkway in the Ulu Temburong National Park in Brunei. In his right hand William is holding a piece of ripe Ficus punctata fruit collected from a nearby fruiting liana.
GIBBON FAMILY TERRITORIES IN BORNEO: Researchers believe that the Ulu Temburong forests host the most dense population of gibbons in the whole of Borneo.
Temburong Bukit Tudal (1)
Temburong Belalong (2)
(1) Bennett et al (1987)A Wildlife Survey of Ulu Temburong
Gibbon familes average 3.5 to 4 individuals and strongly defend their territories with loud early morning calls. The high density and small family territories of gibbons at both sites in Ulu Temburong (Brunei) may be due to the absence of orangutans in Brunei. Orangutansare known to eat unripeF. punctatafigs. Gibbons only eat the ripe figs and therefore cannot compete with orangutans if they are present.