© Andie Ang 2014-2019

ANDIE ANG

Primatologist

Banded Langur (Presbytis femoralis)

 

The banded langur is a species of Asian colobine with black fur and white bands traversing the underside of its body and limbs. An average adult weighs 6.0 kilograms with a body length of 68-80 centimeters. Adapted strictly to an arboreal lifestyle, it is primarily frugivorous, but also consumes young leaves.

At least three subspecies are currently recognized, but its taxonomy is still being debated: East Sumatran banded langur (Presbytis femoralis percura) occurs in east-central Sumatra, Robinson's banded langur (P. f. robinsoni) in the northern Malay Peninsula and Raffles' banded langur (P. f. femoralis) in Singapore and Johor, Malaysia.

 

In August 2016, the Raffles' Banded Langur Working Group was formed to study and conserve this endangered subspecies in Singapore and Malaysia. The first Species Action Plan was also published to guide research and conservation applications. 

 

Raffles' banded langur, Malaysia

Photo by Con Foley

Raffles' banded langur, Singapore

Photo by Nick Baker

Research to date

After three years (2009-2011) of field and laboratory work, I estimate that there are at least 40 Raffles' banded langurs (RBL) in Singapore, double the previous estimate [1]. Infants have also been observed, all believed to be born in June or July over the past three years [1]. In addition, the monkeys have been observed to feed on 27 food plant species, of which approximately half are locally threatened. Furthermore, through genetic studies of their feces, it has been found that the population has a very low genetic variability [2,3]. This low genetic variability is the next challenge for the conservation of the population.

More research is currently being carried out (Jan 2017-present) with three key goals in mind [4]:

Goal 1: To recover and protect RBL in the wild, ensuring that:

  • the rainforest habitat of the taxon is intact, where necessary restored

  • wild populations are connected where needed

  • genetic and demographic viability are ensured

Goal2: To gather key data through ongoing studies, ensuring that:

  • its taxonomy and systematics are clarified, and the biology and ecology understood

  • long-term monitoring and conservation research are in place

 

Goal 3: To secure the necessary resources and commitments for long-term conservation, ensuring that:

  • there is strong public awareness and government support

  • cross-country collaboration is strengthened and long-term financial support has been secured 

 

References

[1] Ang A., M. Ismail and R. Meier, 2010. Reproduction and infant pelage coloration of the banded leaf monkey, Presbytis femoralis (Mammalia: Primates: Cercopithecidae) in Singapore. Raffles Bulletin of Zoology 58, 411-415

[2] Ang A., A. Srivathsan, B.M. Md.-Zain, M. Ismail and R. Meier, 2012. Low genetic variability in the recovering urban banded leaf monkey population of Singapore. Raffles Bulletin of Zoology 60, 589-594

[3] Srivathsan A., A. Ang, A.P. Vogler and R. Meier, 2016. Fecal metagenomics for the simultaneous assessment of diet, parasites, and population genetics of an understudied primate. Frontiers in Zoology 13, 17

[4] Ang A., V. D'Rozario, S.L. Jayasri, C.M. Lees, T.J. Li and S. Luz, 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