Cao-vit Gibbon on Brink of Extinction: Only 74 Individuals Remain in Northern Vietnam The Cao-vit gibbon (Nomascus nasutus), the world's second-rarest ape, faces critical extinction risk with only 74 individuals remaining in the wild as of 2023. This population estimate, derived from advanced vocal fingerprinting technology, is 38% lower than previous estimates of 120 individuals and represents more precise data rather than an actual recent decline. The species is confined to a single forest fragment smaller than 3,000 hectares on the Vietnam-China border, where it was rediscovered in 2002 after being presumed extinct since the 1960s. The dramatically small population size exposes the species to severe risks including loss of genetic diversity, inbreeding, and vulnerability to catastrophic events such as disease or natural disasters.
Conservation efforts since 2002 have stabilized the population through habitat protection, anti-poaching patrols, and transboundary cooperation between Vietnam and China. Fauna & Flora and local partners have implemented acoustic monitoring and thermal drone technology to track populations accurately, while also working to restore forest habitat and establish protected corridors to expand the species' extremely limited range. However, experts emphasize that current protected habitat can support a maximum of 200 gibbons even under optimal conditions, necessitating urgent habitat restoration and potential translocation efforts to new forest areas. The species' slow reproduction rate and dependence on slow-maturing fruit trees further complicate recovery prospects.
