This primer provides an overview of the Javan gibbon, an endangered primate found primarily in the forests of Java, Indonesia. It covers the history of the species, its physical characteristics, its behavior, and its current conservation status. It
From Wikipedia
The silvery gibbon, also known as the Javan gibbon, is a primate in the gibbon family Hylobatidae. It is endemic to the Indonesian island of Java, where it inhabits undisturbed rainforests up to an altitude of 2,450 m (8,040 ft). It has been listed as Endangered on the IUCN Red List since 2008, as the wild population is estimated to comprise less than 2500 mature individuals.