Raffles' banded langur, Singapore
Photo by Andie Ang
Raffles' Banded Langur (Presbytis femoralis)
The Raffles' banded langur is a species of Asian colobine with black fur and white bands traversing the underside of its body and limbs. An adult weighs between 6 kg and 8 kg, reaching 60 cm to 65 cm in body length with a tail of up to 80 cm.
The Raffles' banded langur occurs in Singapore and southern Peninsular Malaysia (states of Johor and Pahang). Globally, there may be fewer than 400 individuals left, with 72 in Singapore and approximately 300 in Malaysia [1]
In Singapore, a total of 61 plant species have been identified as food of the langurs [1,2]. They eat native plants such as rambutan (Nephelium lappaceum) seeds and sea apple (Syzygium grande) fruits, and non-native plants such as rubber tree (Hevea brasiliensis) leaves and African tulip (Spathodea campanulata) flowers.
Loss of habitats due to urban development reduces resources and space for the population to grow. Habitat fragmentation separates the prevents the mixing of langur groups. Road accidents and mortalities happen when langurs attempt to cross roads to get from one forest patch to another. Over time, as the population size becomes smaller, the gene pool of the species decreases, resulting in inbreeding and poor genetic health [3]. A lack of awareness of the existence of the species will also hamper conservation efforts.
Raffles' banded langur, Singapore
Photo by Nick Baker
Species Action Plan
In August 2016, the Raffles' Banded Langur Working Group was formed to study and conserve this critically endangered species in Singapore and Malaysia. The first Species Action Plan was also published to guide research and conservation applications, with three key goals in mind [4]:
Goal 1: To recover and protect RBL in the wild, ensuring that:
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the rainforest habitat of the taxon is intact, where necessary restored
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wild populations are connected where needed
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genetic and demographic viability are ensured
Goal2: To gather key data through ongoing studies, ensuring that:
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its taxonomy and systematics are clarified, and the biology and ecology understood
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long-term monitoring and conservation research are in place
Goal 3: To secure the necessary resources and commitments for long-term conservation, ensuring that:
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there is strong public awareness and government support
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cross-country collaboration is strengthened and long-term financial support has been secured
References
[1] Ang A. and Jabbar S., 2022. Raffles' banded langur: the elusive primate of Singapore and Malaysia. World Scientific, Singapore, 100 pp.
[2] Srivathsan A., Ang A., Vogler A.P. and Meier R., 2016. Fecal metagenomics for the simultaneous assessment of diet, parasites, and population genetics of an understudied primate. Frontiers in Zoology 13, 17-29
[3] Ang A., Srivathsan A., Md.-Zain B.M., Ismail M. and Meier R., 2012. Low genetic variability in the recovering urban banded leaf monkey population of Singapore. Raffles Bulletin of Zoology 60, 589-594
[4] Ang A., D’Rozario V., Lakshminarayanan J., Lees C.M., Li T.J. and Luz S., 2016. Species action plan for the conservation of Raffles’ banded langur (Presbytis femoralis femoralis) in Malaysia and Singapore. IUCN SSC Conservation Breeding Specialist Group, Apple Valley, MN, USA, 31 pp.