Rediscovered a sub-population of the critically endangered Delacour’s langurs in the Huong Son special-use forests of Ha Noi
Delacour’s langur (Trachypithecus delacouri) is endemic primate to Vietnam and also among the top 25 most threatened primate in the world. The species restricted to the forest on limestone situate in the border of Hoa Binh, Thanh Hoa, Ninh Binh, Ha Nam and Ha Noi provinces. Early of the 2000s, the population of Delacour’s langur was estimated to occur in 19 locations with a total of 50-57 groups and 281-317 individuals, of which the Huong Son special-use forest was estimated to have 6 groups and 27 individuals[1]. Fifteen years later, the langur population in the Huong Son special-use forests was thought to be extirpated after surveys[2].
Since 2017, CCD has conducted an intensive studying program to search for the existence of Delacour’s langur in its known habitats to assist better protection and population recovery efforts. Under the program, CCD successfully confirm the second largest population of this species in the Kim Bang Forest in 2018[3] and a group in the Lac Thuy forests in 2021[4].
December 2022, CCD under the continuing survey program, CCD team found a group of at least five Delacour’s langurs in the Huong Son special-use forests, marking this place as the third most important strongholds for the langurs still exist[5]. CCD is continuing its conservation effort for this critically endangered langur through having a detail survey in Huong Son Forest and other known habitats and propose habitat restoration and connecting the existing wild sub-populations through multi-dimension conservation approaches to create a large, safe landscape for the survival and thriving of Delacour’s langurs and other critically endangered species.
Nhan Dan Newspaper published an article about the finding. Details are in the link below
https://nhandan.vn/theo-dau-vet-vooc-quy-hiem-ngay-giua-ha-noi-post732728.html
[1] Nadler, T. (2004). Distribution and status of the Delacour’s langur (Trachypithecus delacouri) and recommendations for its long-term conservation. In T. Nadler, U. Streicher, & T. L. Ha (Eds.), Conservation of primates in Vietnam. Frankfurt Zoological Society and Cuc Phuong Endangered Primate Rescue Center.
[2] Nadler, T. (2015). The critical status of the Delacour’s langur (Trachypithecus delacouri) and the call for a National Action Plan. Vietnamese Journal of Primatology, 2(4), 1–12.
[3] Trinh, D. H., & Nguyen, T. A. (2018). Report on population survey for the Delacour’s langur (Trachypithecus delacouri) in Kim Bang forests, Ha Nam province, Vietnam. Center for Nature Conservation and Development.
[4] Trinh, D. H., Le, T. A., & Lo, V. O. (2021). Report on the census of Delacour’s langur (Trachypithecus delacouri) population in the Huong Son special-use forest and Lac Thuy forests. Center for Nature Conservation and Development.
[5] Lo, V. O., & Lau, A. K. (2022). Report on the survey of primates in the Huong Son special-use forest, Ha Noi, Vietnam. Center for Nature Conservation and Development.