In a collaborative effort between international primate experts and conservationists, the IUCN Species Survival Commission (SSC) Primate Specialist Group, Mandai Nature, Re:wild, German Primate Center and Primate Conservation Inc. launched the Asian Langurs (Presbytis) Conservation Action Plan 2024–2034 (Ang et al., 2024, IUCN) on 25 August 2024. This landmark initiative, the first genus action plan for a threatened group of Asian monkeys, calls for unified conservation efforts across Southeast Asia, outlining key priorities for the next decade to prevent the extinction of 20 Asian langur species in Brunei, Indonesia, Malaysia, Myanmar, Singapore and Thailand.

Habitat loss through urban and economic development, natural resource extraction, logging, monoculture plantation and forest fires has been identified as a key threat facing Asian langurs. Other threats include hunting for their meat and bezoar stones, human–wildlife conflicts arising from crop foraging, poaching for the illegal pet trade, and roadkill. Over 85% of Asian langur taxa are threatened with extinction. Among the 20 species highlighted in the Action Plan, two (the Bornean banded langur Presbytis chrysomelas and Raffles’ banded langur Presbytis femoralis) are on the IUCN list of The World's Top 25 Most Endangered Primates.

The Action Plan was developed following a symposium and conservation planning workshop held during the 29th International Primatological Society Congress in Kuching, Malaysia, in August 2023. Primate experts and conservation practitioners identified gaps and threats and outlined the corresponding conservation actions needed to mitigate or reverse the decline of langur populations. Thirty-three knowledge experts and conservationists from 23 institutions contributed to the Action Plan, providing a comprehensive roadmap for local and international conservation groups, governments, communities, academic institutions, zoos and wildlife centres. Nine conservation priorities were identified: (1) improve knowledge on the distribution, population size, and ecological and taxonomic relationships of each Presbytis taxon; (2) improve protection of core habitats, restore habitat connectivity and implement fire control measures; (3) raise local, national and global awareness; (4) integrate and collaborate with local communities in conservation tourism; (5) develop best practice guidelines for ex situ care of Presbytis langurs; (6) work with governments to improve the legal protection of Presbytis; (7) foster collaboration in sites with existing efforts for other taxa; (8) secure funding; and (9) create a global network of Presbytis researchers and conservation practitioners. The Action Plan can be accessed at portals.iucn.org/library/node/51546.

In conjunction with the launch of the Action Plan, an international Colobine Monkey Day was inaugurated on 25 August. Colobine monkeys (subfamily Colobinae) are medium-sized, largely arboreal primates known for their complex, multi-chambered stomach enabling them to digest tough plant material. They are a diverse group of 83 recognized species, including Asian langurs, snub-nosed monkeys and African colobus monkeys. We hope this annual celebration and the publication of the Action Plan will raise awareness for colobine monkeys and spur conservation actions for Asian langurs.

A Critically Endangered Raffles' banded langur Presbytis femoralis with its young. Photo: Andie Ang.