The Endangered François’s langur Trachypithecus francoisi lives in limestone forests of Viet Nam and China. During the Qing Dynasty it was widely distributed in China, and in the early 1880s the population numbered c. 15,000. This decreased markedly, however, during the 20th century, and by 2010 the wild population numbered only 1,660–1,700, in 203–208 groups. Of these, 27 groups with a total 200 individuals were in Chongqing (Han et al., 2013, Oryx, 47, 128–133).

To evaluate the current status of François’s langur, during May–December 2024 we carried out line transect surveys of populations identified within the previous 2 years, and verified the latest reports on the population size of langurs in nature reserves, through on-site interviews, with the support of the Wildlife Conservation Monitoring Center of the State Forestry and Grassland Administration. To estimate the current population of this langur in China, we combined the findings of these surveys and interviews with our monitoring of other populations with line transects and camera traps during 2016–2020.

We estimate that the population of François’s langur in China is now 2,026–2,044, in 263–265 groups, in Guizhou (1,231–1,238 individuals in 154–155 groups), Chongqing (255 individuals in 31 groups) and Guangxi (540–551 in 78–79 groups). The main threats to the species are habitat disturbance, climate change and its low genetic diversity. However, through continued management and research, the population of this Endangered primate is expected to continue to recover and expand its range.

I acknowledge support from the National Natural Science Foundation of China (No. 32460119).