The recovery of the critically endangered white-cheeked gibbon (Nomascus leucogenys) in Xuan Lien Nature Reserve

The conservation program for the critically endangered white-cheeked gibbon (Nomascus leucogenys) is a long-term conservation program that has been initiated by the Center for Nature Conservation and Development (CCD) with a focus on Xuan Lien and Pu Hoat Nature Reserves (NR). The CCD team has just completed the third monitoring trip in August 2019 in Xuan Lien NR. The monitoring results indicated a high concentration of gibbon groups in the fixed monitoring areas. A total of 24 groups with at least 62 individuals were confirmed in the two fixed monitoring areas of Pha Pha mountain located on the Pu Nam Mua mountain range and Vung Bo mountain ridge top. The record in this survey is double as much as the baseline data in 2011 for the same areas (Nguyen et al. 2012). Gibbon is territorial, hence, the monitoring of gibbons in the fixed listening posts can help identify the gibbon population trend. This survey shows a positive evidence of the recovery for this critically endangered species in Xuan Lien while their populations are extirpating in many other known habitats. The recovery of the white-cheeked gibbon population is an encouraging sign of the conservation efforts made in Xuan Lien in particular and in Vietnam as the whole.