There are four species of crested gibbon found in Lao PDR: Western Black Crested Gibbon (Nomascus concolor); Northern White-cheeked Gibbon (N. leucogenys); Southern White-cheeked Gibbon (N. siki); and Yellow-cheeked Gibbon (N. gabriellae). All species are CITES Appendix 1 species with the first two, Western Black Crested and Northern White-cheeked Gibbon, listed as critically endangered, the highest category of threat, and the other two as endangered, the second highest category. The majority of the world's N. leucogenys and N. siki populations inhabit Lao PDR, more than in China or Vietnam, which is due mainly to relatively large areas of forest remaining intact and difficult for humans to access. The range for N.leucogenys is believed to stretch from the far northeast of Lao PDR to the vicinity of the Nam Kading River in Nam Kading NPA in central Lao PDR.
Although information on gibbons in Lao PDR is limited, Nam Et-Phou Louey NPA has been identified by the Gibbon Conservation Action Plan for Lao PDR 2011-2020 as having significant population of Northern White-cheeked Gibbons in the country. Nam Kading NPA has been identified as also having a significant population of Southern White-cheeked Gibbon.
The major threat to gibbons is hunting. Local consumption of gibbons as a source of protein in rural areas still occurs, and many are sold as pets or for their bones, which have purported medicinal value. Although traditional taboos against hunting gibbons exist, these are currently degrading under new social pressures, and thus opportunistic hunting still occurs.
WCS is working directly with the Lao government to improve the institutional structure and management of key protected areas with gibbon populations and has a long-term goal of supporting these areas into the future until the government has adequate resources and capacity to continue activities on its own. Awareness-raising in villages around protected areas has led to increased understanding of the global importance and laws regarding gibbons and other threatened and endangered species. Coordinated and ongoing enforcement of the National Wildlife Law of 2008 has also shown positive results in protecting gibbon populations. WCS is planning a host of livelihood and conservation interventions with communities around gibbon habitat, such as community-based ecotourism.