The Bornean Gibbon Hylobates muelleri is one of two species of gibbon inhabiting the island of Borneo, the other being the Agile Gibbon Hylobates agilis. The species is endemic to Borneo, and is confined to tall primary rainforest in lowland and lower montane areas.

Gibbons are exclusively arboreal, and do not descend to the ground. The species may continue to survive in forests affected by logging, as long as sufficient tall trees survive in close proximity to allow ease of movement from one tree to the next. In practice, most logged areas support few or no gibbons.

Gibbons occur in small family groups generally comprising a male, female and their young. The whooping call of adult gibbons early in the morning is, perhaps, the most iconic sound of Borneo's rainforest.

Fur colour of the Bornean Gibbon is typically grey-brown, though this can vary greatly. The brow is pale cream to white.

Pictured here is a typical example of the subspecies H. m. funereus (or Northern Grey Gibbon), which occurs in Sabah and northern parts of both Sarawak and East Kalimantan. In this subspecies the front part of the scalp and upper chest are dark brown.    

Figs 1 and 3 : A Bornean Gibbon feeds on small fruits and young leaves in the early morning sun at Danum Valley, Sabah, Borneo.

Fig 2 : Lowland primary rainforest at Danum Valley, Sabah, Borneo.




Order : PRIMATES
Family : Hylobatidae
Species : Hylobates muelleri

Head-body length : 42-47 cm
Tail length : no tail
Weight : 5-6.4 kg


References : M2