Bioacoustics of Nomascus annamensis

Status and Conservation. CITES Appendix I. This newly described species has not been assessed on The IUCN Red List. The presence of the Northern Yellow-cheeked Crested Gibbon has been confirmed in 18 protected areas: Dak Rong, Phong Dien, Ba Na-Nui Chua, Song Thanh, Ngoc Linh, and Kon Cha Rang nature reserves and Bach Ma and Chu Mom Ray national parks in Vietham; Dong Phou Vieng, Xe Sap, Xe Bang Nouan, Phou Xiengthong, Dong Amphan, Dong Houa Sao, and Xe Pian biodiversity conservation areas in Laos; and Virachey National Park in Cambodia. In Vietnam, ¢.200 groups have been recorded between 2000 and 2011, although this represents a minimum number. Key populations are thought to occur in the contiguous Dak Rong and Phong Dien nature reserves, and additional important populations may occur in Kon Cha Rang Nature Reserve and Song Thanh, Ngoc Linh, and Kon Cha Rang nature reserves and surrounding forests. Although data are lacking, populations in Laos are likely significant, but it is inferred that they are declining, with none in effectively managed protected areas. Some locations in Laos, such as Xe Sap National Protected Area, afford good natural protection. Populations in Cambodia are likely to be very important, the most significant being in Virachey National Park with an estimate of over 10,000 individuals, although based on very limited survey data. The adjacent Veun Sai-Siem Pang Conservation Area has a population estimate of ¢.500 groups and is currently under management. The Northern Yellow-cheeked Crested Gibbon is threatened by habitat loss, hunting, and collection for the pet trade. In Cambodia, large areas of habitat in Virachey National Park are being cleared for rubber plantations, and a mining concession over most of the protected area poses threats to this core population. Compared with the more northerly distributed species of Nomascus , however, populations of the Northern Yellow-cheeked Crested Gibbon are relatively robust and intact.