Hope for the Cao Vit Gibbon

An October 2012 census shows that the population of Cao Vit gibbons has risen to 129 individuals from the 110 counted in 2007.  This survey was funded by a 2011 Wildlife Without Borders grant of  $53,404.00 to Fauna and Flora International (FFI) to conduct a trans boundary census and a review of the management plans to protect the radiant Cao Vit gibbon (Nomascus nasutus), also known as the eastern black crested gibbon.  It is the rarest ape in the world after its closest relative the Hainan gibbon. It was found in just one patch of forest on the China -Vietnam border where a FFI survey team rediscovered it in 2002. It is listed as one of the world’s 25 most endangered primates.

In 2012 a complete population census of the gibbons was conducted by 31 people led by FFI.  They spent two weeks in the Cao Vit Gibbon Conservation Area. Observation posts were set up at 18 vantage points spread throughout the core zone of the conservation area.

Gibbon pairs strengthen bonds and mark their territory by singing loud and elaborate duets, usually at dawn. Calls can be heard up to a kilometre away and are distinct between males and females. During the census, two- or three-person teams spent eight hours (from 4 a.m. to midday each day) at the observation posts, where they listened for gibbon song and attempted to visually confirm the number of gibbons in each group.

When Fauna and Flora International first located this population in 2002 they were only able to confirm 26 individual gibbons. Of course this animal remains in a very precarious situation but at least its numbers are increasing. The species is benefiting from conservation activities with the local communities, habitat restoration, creating alternative livelihoods, patrolling, and trans-boundary work.