SINGAPORE – The rare Raffles’ banded langur is slowly bouncing back from the brink of extinction and its numbers are likely to double from 75 to more than 150 in the next 15 years, said experts.
The shy tree-dwelling monkey - found only in Singapore and southern peninsular Malaysia - was in the 1990s predicted to die out within 40 years due to habitat loss and fragmentation, said Mandai Nature and Oxford Brookes University in a joint statement on Tuesday.
Mandai Nature is the conservation arm of the Mandai Wildlife Group and Oxford Brookes is a British university whose researchers teamed up with their counterparts in Singapore for the study.
Numbers of the Raffles’ banded langur - distinguished from the common long-tailed macaques by its black fur and white bands - hit a low of 10 in the 1980s, but have slowly been climbing in recent years, the statement added.
A study published in the Raffles Bulletin of Zoology journal in September found that the population of the langur, which is Singapore’s largest primate species in the wild, is expected to go up to more than 240 monkeys by 2071.
Primate expert Andie Ang, who is one of the authors of the study, said: “The results presented in our paper show that with the right protection and management measures in place, we can bring a species back from the brink of extinction.
“However, these endeavours demand steadfast dedication in the field, strong partner collaborations and adequate financial support.”
Dr Ang helms the Raffles’ Banded Langur Working Group, which was formed in 2016 to drive conservation efforts of the elusive animal. She said it remains one of the most threatened primates in the world.
Despite the optimistic projections in the latest study, the researchers said even a small uptick in deaths can be damaging for the population of Raffles’ banded langurs in Singapore.
In the statement, Ms Amy Woolloff, the lead author of the paper, said: “Although our model shows the population is likely to continue growing in the next 50 years, they remain vulnerable to not only deaths from roadkill, but also unpredictable events such as diseases and extreme weather.”
Between 2017 and 2023, four langurs or about 5 per cent of the total population in Singapore, died in road accidents.
Ms Woolloff said: “To ensure the long-term survival of this species in Singapore, there remains an urgent need to identify more suitable habitats for the Raffles’ banded langurs, to enhance habitat connectivity to prevent deaths occurring from road crossings, and to increase population genetic diversity with conservation translocation”.
Researchers found that the loss of unprotected habitat is the greatest threat now, while the most effective short-term management strategy was to improve links between patches of forest areas in their current range.
Speaking to The Straits Times, Dr Ang said one high priority site is the forest opposite Thomson Nature Park, close to the spot where two Raffles’ banded langurs were killed on the Seletar Expressway in late 2022.
The site is slated for residential development, according to the Urban Redevelopment Authority’s 2019 masterplan.
Mr Lim Liang Jim, who is the National Parks Board (NParks) group director of conservation, said the board has been taking steps to protect and shore up key habitats for the langur.
These include planting trees that have spreading canopies, and installing rope bridges to allow the animals to cross safely.
Mr Lim said: “In assessing where to situate the rope bridges, NParks worked closely with the Raffles’ Banded Langur Working Group to locate them where the langurs have been observed to habitually cross. NParks will continue to work with the community to come up with strategies to strengthen the survival of our native langurs and other wildlife.”
The Raffles’ Banded Langur Working Group is managed and funded by Mandai Nature, and its members include representatives from NParks, Singapore universities, nature groups, agencies from Malaysia and the Jane Goodall Institute (Singapore).
