A Review of François' Leaf MonkeyTrachypithecus francoisi(sensu lato) in Lao PDR

A previously overlooked population of François' leaf monkey, Trachypithecus francoisi (sensu lato), was identified as endemic to Lao PDR, specifically the taxon laotum. This discovery, made in 1920, remained largely unrecognized for seven decades until wildlife surveys in the 1990s revealed substantial populations within Phou Hinpoun and Hin Namno National Protected Areas (NPAs). The study also documented smaller, localized populations in Nakai—Nam Theun NPA and Muang Vilabouli, with potential taxonomic significance. While healthy populations persist in large karst landscapes, those in smaller or non-calcareous areas face high vulnerability to hunting-induced extinction. The research highlights critical knowledge gaps regarding the species' distribution, taxonomy, and threats, emphasizing the urgent need for further surveys, particularly in northern regions where conservation pressures are greatest.

Duckworth, J. W., Boonratana, R., Robichaud, W. G., & Timmins, R. J. (2010). A Review of François’ Leaf MonkeyTrachypithecus francoisi(sensu lato) in Lao PDR. Primate Conservation, 25(1), 61–79. https://doi.org/10.1896/052.025.0111