Hoolock gibbons  (Hoolock hoolock and Hoolock leuconedys)

Brachiation: In some primates, a method of locomotion when the animal swings hand over hand from branch to branch.
Deciduous: A plant that sheds its leaves at the end of the growing season.
Frugivorous: Fruit eating/ fruit eater.
Monogamous: Having only one mate during a breeding season, or throughout the breeding life of a pair.
Sexual dimorphism: When males and females of the same species differ in appearance.
Suspensory behaviour: Locomotory and postural habits characterized by hanging or suspension of the body below or among branches rather than walking, running, or sitting on top of branches.

1. IUCN Red List (January, 2009)
   http://www.iucnredlist.org
   
2. Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
   
3. CITES (January, 2004)
   http://www.cites.org
   
4. Walker's Mammals of the World Encyclopedia (January, 2004)
   http://www.press.jhu.edu/books/walkers_mammals_of_the_world/primates/primates.hylobatidae.hylobates.html
   
5. Animal online (January, 2004)
   http://www.animals-online.be/primates/gibbons/hoolock_gibbon.html
   
6. United Nations Environment Programme, World Conservation Monitoring Centre (January, 2004)
   http://www.unep-wcmc.org/index.html?http://www.unep-wcmc.org/species/data/species_sheets/hoolock.htm~main
   
7. Gibbon Conservation Centre, Hoolock Gibbon (January, 2004)
   http://www.gibboncenter.org/hoolock.htm