Hylobates lar

Primarily diurnal and strictly arboreal, they travel and forage in the forest canopy, feeding mainly on fruit supplemented by leaves, flowers and insects. Social structure centers on long-term monogamous pairs that defend a territory with daytime duets; families (pair plus offspring) maintain and patrol a home range, avoid ground travel when possible, and use vocalizations and scent marking to communicate.

Pairs reproduce seasonally or opportunistically depending on food; after a gestation of roughly 6–8 months, females give birth to a single infant. Young are dependent for >1 year, weaning around 1 year, with interbirth intervals commonly 2–3 years; juveniles eventually disperse to find mates or form new pair bonds.

Adaptations for brachiation include very long forelimbs, hook-like hands, and highly mobile shoulder joints; they lack a tail. They possess a gular (throat) sac for amplifying calls, show limited sexual dimorphism, and exhibit regional coat-color variation, with white hands/feet and facial rims a diagnostic trait.

Endemic to Southeast Asian forests (from Myanmar and Thailand through Malaysia and parts of Indonesia), white-handed gibbons historically occupied continuous lowland and hill forests. Over the past century, their range has fragmented from logging, agricultural conversion (notably oil palm), hunting, and capture for the pet trade, reducing formerly continuous populations to isolated patches.

Hylobates lar is threatened (IUCN: Endangered in many assessments) due to habitat loss, fragmentation, hunting and illegal trade. Conservation actions focus on habitat protection, anti-poaching enforcement, community engagement, and rescue/rehabilitation programs; long-term survival depends on restoring forest connectivity and reducing human pressures.