The grey-shanked douc langur Pygathrix cinerea is a Critically Endangered primate primarily occurring in Vietnam and adjacent areas of Cambodia. Hunting and trapping are driving population declines, and road construction and forest conversion are further fragmenting the species’ already limited habitat. Nearly 2,000 individuals have been recorded in protected and unprotected forest across six provinces in Vietnam (Quang Nam, Quang Ngai, Binh Dinh, Phu Yen, Gia Lai and Kon Tum), 50% of which occur in unprotected areas with limited habitat and few recent records.

In June 2024, we discovered a new population of the grey-shanked douc langur in Khe Lim Forest, Dai Loc District, Quang Nam Province. Our short survey confirmed the presence of a group consisting of one adult male, two adult females, two subadults and two juveniles. The group was located in a 17 ha forest pạtch characterized by mountainous terrain, at an altitude of 600–1,100 m. During subsequent fieldwork in August 2024, including interviews with local communities, we identified two additional sites occupied by the grey-shanked douc langur in Khe Lim Forest. These areas are significantly affected by ongoing road construction and daily resource collection by local communities in the buffer zone, highlighting the urgent need for conservation interventions to protect the remaining langur populations.

The discovery of a new population in Khe Lim Forest suggests that additional populations of grey-shanked douc langur may still exist in other unsurveyed forest areas. We recommend a comprehensive survey of the entire Khe Lim Forest, and enhanced outreach efforts with local communities in the buffer zones. This approach will help establish conservation measures to protect other unknown, isolated populations of the grey-shanked douc langur.

Grey-shanked douc langur Pygathrix cinerea population recorded in the Khe Lim Forest in June 2024. Photo: Tai Anh Nguyen.