Proboscis monkeys are endemic to Borneo and are critically threatened by deforestation for palm oil - their highly specialised diet and social structure make them extremely vulnerable to habitat loss.
Proboscis monkey welfare is threatened primarily by habitat destruction. Their specialised digestive systems, adapted for fermentation of tannin-rich leaves, mean they cannot simply switch to alternative food sources in degraded habitats. Captive proboscis monkeys are notoriously difficult to maintain due to dietary needs and are rarely kept outside their range countries. In the wild, forest fragmentation creates isolated populations unable to maintain viable social groups. Welfare harms from habitat loss include nutritional stress, increased predation vulnerability during river crossings between fragments, and social disruption. Palm oil boycotts and certified sustainable sourcing are the most direct consumer actions.