Fauna & Flora International surveys unexplored gibbon haven

Fauna & Flora International (FFI), with Kunming Institute of Zoology, has discovered of the largest population of the western black crested gibbon (Nomascus concolor) known in the world.

Our team surveyed 40,000 hectares of dense mountainous forest in China’s Yunnan Province and found about 400-500 individuals in roughly 110 groups. This is also the most densely populated area for the species known in the world.

The survey took place in and around the Ailaoshan National Nature Reserve, in Xinping County. The area had never been properly surveyed for western black crested gibbons before, although the gibbons were known to be present.

The gibbon is listed as Critically Endangered on the IUCN Red List due to a continuing global population decline resulting from habitat fragmentation and loss. Only about 1000 individuals are believed to survive across southern China, northern Vietnam and northwest Laos. The new survey suggests Xinping County is one of the most important locations for the survival of the species.

Ailaoshan National Nature Reserve was created in the 1980’s to protect the western black crested gibbon and covers 67,700ha of steep mountainous terrain. Yunnan Province hosts the highest biodiversity of plants and animals of China, as well as the highest diversity of gibbons.

The survey team, which included staff of the nature reserve, used a combination of in-depth interviews with local communities and 120 listening posts to estimate the number of gibbons in the area.

Gibbons are hard to spot in the thick forest canopy but have distinct calls that travel up to 1 km, so listening posts are the best way to estimate population sizes. Using GPS, the team mapped out where they heard gibbon song and estimated out how many individuals and family groups could be living in the forest.

FFI recommends that the reserve strengthens its community engagement, both through education and active participation in protecting the western black crested gibbon.