Order : PRIMATES
Family : Hylobatidae
Species : Hylobates pileatus

Head-body length : up to 60 cm
Tail length : no tail
Weight : up to 7 kg

The Pileated Gibbon, also known as 'Capped Gibbon' or 'Crowned Gibbon', is an endangered primate which occurs in parts of eastern Indochina. It inhabits moist, tall forest in lowland, hill and lower montane elevations to around 1500 metres.

Their diet comprises fruits (especially figs), young shoots, young leaves and some insects.

Family groups are small, typically up to 4 individuals. The species appears to be more shy than the White-handed Gibbon which inhabits territories to the west of the Pileated Gibbon.

Adult males are mainly black, with a white face-ring or brow-band, pale tufts over the ears, white fur around the groin, and white hands (like the White-handed Gibbon). Adult females are buff, with dark fur on the chest and belly (which becomes more extensive with age), and black fur on the crown. Juveniles and infants are pale throughout.

In the extreme west of its range, which includes  Khao Yai National Park, Thailand, there is a zone of overlap with the White-handed Gibbon Hylobates lar. This overlap zone was once considerably larger, but much of the lowland forest in the area is now gone. Hybridization between Hylobates pileatus and Hylobates lar has been documented in this zone.

The Pileated Gibbon occurs in southeastern Thailand, southwestern Laos, and northern/western Cambodia. Its historical range may have included southern Vietnam (Roos et al, 2014).

Figs 1 and 2 :  Adult male searching for ripe figs.

Fig 3 :  Adult female - note the presence of dark fur on the chest, and a small, black cap.

Fig 4 :  Juvenile - note the absence of a black cap.

All photos from Khao Yai National Park, Thailand. Photos thanks to Terry McNeice and Ng Bee Choo.


References : 

Brockelman, W., Geissmann, T., Timmins, T. & Traeholt, C.  (2008). Hylobates pileatus. The IUCN Red List of Threatened Species 2008: Downloaded on 01 May 2019.

Francis, C.M., 2001. Mammals of South-east Asia. New Holland.

Roos, C., Boonratana, R., Supriatna, J., Fellowes, J. R., Groves, C. P., Nash, S. D., Rylands, A. B. & Mittermeier, R. A. (2014). An updated taxonomy and conservation status review of Asian primates. Asian Primates Journal 4(1): 2-38.