This species of tree-dwelling, diurnal small ape grows to about 8 kg. (18 lbs.) and subsists on fruit and leaves. They have slender bodies, and no tails. Males are generally black, with a white halo, and females are blondish, or grayish, with a black cap and chest. Found in tropical Southeast Asian forests, the pileated gibbon uses its long arms to throw itself from tree to tree, covering gaps of ten meters or more. It has a monogamous mating system, with newborns appearing every two or three years. The males and females communicate via “duetting,” which consists of vocalizations between the breeding pair, maintaining both their bond and establishing the territory they share. The maximum life span is 34 years in captivity.
It’s estimated that there were between two to three million pileated gibbons in Thailand alone, before deforestation began in that country in the 1960s. A 1975 study put the number at 13,600. The International Union for the Conservation of Nature and Natural Resources currently classifies the pileated gibbon as “vulnerable,” which is an improvement over its 1994 classification as “endangered”. Currently, it still faces a high risk of extinction in the wild in the medium-term future, due both to habitat degradation, and to hunting for food and for sale.