where I got this from

The Javan silvery gibbon (Hylobates lar moloch) is almost exclusively restricted to primary tropical rain forest below approximately 1500 meters.

This vegetation type, which has a really large biomass and has a whole load of different species, is inhabited by a large number of animals. The tropical lowland rain forest of South-East Asia contains the most luxuriant and most complex ecosystems on earth.

The ecological niches are extremely manifold. Some animal species are ecological specialists and, as such, are equipped with niche-specific physiological, morphological and ethological characteristics; others are generalists. Each species is limited to certain factors of space and time and, accordingly, shows particularities in the use of resources. (Garrghh! Too many very long words, and as I've said before, I really am not a biologist, and I'm not even gonna try and put that into english)

The site linked to above is some guys entire paper on the silvery gibbon as a component of the tropical rain forest of West Java. He goes on and on about:

• technique and style of locomotion
• diet and feeding
• avoidance of predators
• female song bout
• home range and territory

H.l.moloch is the sixth member of the Hylobatidae on whose way of life a study - based on long-term field observation - is presented.