The northern white-cheeked Nomascus leucogenys is Critically Endangered, where the buff or southern yellow-cheeked gibbon Nomascus gabriellae is Endangered. Does it matter that much ..., nog because all gibbon species of the genus Nomascus in Vietnam (5 species) are between ENDANGERED or CRITICALLY ENDANGERED.The Gibbon SSP actually focuses on three species: lar, white-cheeked, and Siamang.
Member Zoos — Gibbon SSP
I may sound smug, but that is further from the real issues ..., all face the same threats from people living off the forests in IndoChina (in this case central and south Vietnam and central Cambodia). As the species do not normally take up a huge amount of space ..., it could be possible to step away from just trying to secure sustainability in the 3 afore-mentioned gibbon species.