Hylobatidae, from Greek ὕλη (húlē, “woods, forest”) and Greek βαίνω (baínō, “to wander, to stroll”), means “one who haunts the woods”, in reference to the fact that these animals are fiercely territorial, defending their boundaries with vigorous vocal and visual displays.

Common names of members

Gibbons.

Distribution  

Southeast Asia.

Size

Their heights range from 42-59 cm to 74-89 cm, and their weights range from 4.4-7.6 kg to 10.7-11.9 kg.

Morphology

These animals are special in that their wrists can move in two directions, much like a ball and socket joint. This lessens the strain on the shoulder joint and significantly lowers the energy required in the upper arm and body. Along with having lengthy hands and feet, they also have a deep split between their first and second fingers. Usually black, gray, or brownish in color, their fur frequently has white patterns on their face, hands, and feet. When an animal calls, the enlarged neck sac in certain species expands to act as a resonating chamber. In certain species, this structure can grow to be rather large—sometimes matching the size of the animal's head. 

Habitat & Ecology

Dense canopy rainforest.

Diet

They mostly eat fruit, although they also occasionally eat leaves, twigs, insects, flowers, and bird eggs.

Reproduction 

Although they are often considered monogamous, there is no hegemony of this behavior. Resident males are unable to monopolize resident females' matings.  Long-term social partners are often distinct from sexual partners in their populations.

Total species known

20

Species in the collection

1

Species in Hong Kong

0

Reference

Cowlishaw, G., Dunbar, R. I. M. (2000). Primate Conservation Biology. University of Chicago Press.

Pough, F. H., Janis, C. M., Heiser, J. B. (2012). Vertebrate Life. Pearson.

Macdonald, D. W. (2006). The Encyclopedia of mammals. Oxford University Press. https://doi.org/10.1093/acref/9780199206087.001.0001.

Wilson, D. E.; Reeder, D. M. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference. Johns Hopkins University Press.

Sussman, R.W. (2003). Primate Ecology and Social Structure. Pearson Custom Publishing.

Huang, X., Hu, N., He, K., Guan, Z., Garber, P., Chapman, C., Jiang, X., Fan, P. (2022). Disassociation of social and sexual partner relationships in a gibbon population with stable one-male two-female groups. American Journal of Primatology, 84(7):e23394. https://doi.org/10.1002/ajp.23394.