Global Distribution
Gibbons are found across the Asian continent, representing the Hylobatidae family of apes. They inhabit a broad geographical arc spanning South, Southeast, and East Asia. This family of small apes encompasses 20 distinct species, each adapted to its particular environment within this vast region. Their presence is a defining feature of the forest ecosystems in these parts of the world, with populations predominantly located in tropical and subtropical zones. All 20 species are currently at a high risk of extinction.
Specific Regional Habitats
Gibbons are distributed across 11 countries within Asia, with distinct species occupying different geographical areas. In Southeast Asia, species such as the lar gibbon are found throughout Thailand, Malaysia, and parts of Myanmar, Laos, and Sumatra. The agile gibbon inhabits Sumatra, northern Malaysia, and southern Thailand, while the pileated gibbon is native to southeastern Thailand, western Cambodia, and southwestern Laos.
Further east, various crested gibbon species, like the black crested gibbon, are found in specific regions of southern China, northern Vietnam, and western Laos. The critically endangered Hainan gibbon, with fewer than 30 individuals remaining, is restricted to a small forest patch on Hainan Island, China. Indonesia’s islands, including Sumatra and Borneo, host several species such as the Bornean white-bearded gibbon and the silvery gibbon on Java.
Hoolock gibbons, including eastern and western species, reside in northeastern India, Bangladesh, and Myanmar. The siamang, the largest gibbon species, is found in Sumatra, Malaysia, and Thailand, sometimes sharing habitats with other gibbon types.
Preferred Forest Environments
Gibbons are tree-dwelling apes that primarily inhabit tropical and subtropical rainforests, which provide the dense canopy structure essential for their unique mode of locomotion, brachiation. They are found in various forest types, including lowland dipterocarp, hill dipterocarp, mixed deciduous bamboo, and seasonal evergreen forests, typically not above 1,200 meters elevation. Their specialized wrist joints and long arms enable them to swing swiftly through the trees.
Their arboreal lifestyle means they spend nearly all their time in the upper and middle levels of the forest canopy, rarely descending to the ground. This high-canopy preference allows them to access abundant food sources like fruits, leaves, flowers, and insects, which constitute their varied diet. The continuous canopy also facilitates their territorial defense through loud vocalizations that travel far through the dense forest.
How Human Activity Affects Their Range
Human activities have significantly altered the wild distribution of gibbons, leading to reduced and fragmented ranges. Deforestation, driven by agricultural expansion, logging, and the development of palm oil plantations, is a primary cause of habitat loss in Southeast Asia. This widespread habitat destruction means gibbons are now confined to smaller, isolated forest patches, making their populations more vulnerable.
The construction of roads through previously undisturbed areas further fragments their habitats, increasing access for poachers and disrupting gibbon movement. Such fragmentation can force gibbon groups into conflict with neighboring groups if their territories are diminished. For instance, the Hainan gibbon’s range has shrunk to a tiny reserve, a result of overhunting and rapid island-wide deforestation.
The illegal pet trade also contributes to population decline, as young gibbons are often taken from their mothers, a process that typically results in the death of the mother. These human pressures have led to a dramatic decline in gibbon populations and distribution since 1900, with most species now classified as endangered or critically endangered.