- A rare population of leucistic, or partially white, purple-faced langurs near Sri Lanka’s Sinharaja Forest Reserve has attracted ecotourism interest, even as monkeys in general are perceived by farmers as crop-raiding pests.
- Unlike albinism, leucism causes a partial loss of pigmentation, and researchers have documented around 30 white langurs in the area.
- The unique langurs have helped transform the village of Lankagama into an ecotourism hub, benefiting the local community and conservation efforts.
- The presence of white monkeys across Sri Lanka, including rare cases of albino primates, highlights the island’s rich biodiversity and the need for further research and protection.
COLOMBO — Monkeys were expected to be among the chief culprits identified as Sri Lanka carried out a nationwide survey on March 15 of crop-raiding animals. But in a small village near the Sinharaja Forest Reserve, a UNESCO World Heritage Site, an unusual population of langurs has captured attention, becoming a local tourist attraction.
Purple-faced langurs (Semnopithecus vetulus) are found only in Sri Lanka and typically have a black coat with distinctive facial markings. But near the village of Lankagama, some individuals stand out, with coats that range from completely to partially white. Often mistakenly cited as a case of albinism, where the organism doesn’t produce any melanin, these white monkeys actually exhibit leucism, a partial loss of pigmentation, says Madura de Silva, president of the Wildlife Conservation Society of Galle (WCSG).
It was a survey in 2011 by the WCSG that formally established the presence of these “snow-white monkeys” in Sinharaja, though local folklore describing ghostly white monkeys appearing in forests — regarded variously as omens of good or ill fortune — goes back centuries. During the WCSG survey, researchers documented 30 white langurs among the 14 troops they observed.
Their presence has helped to transform Lankagama into an ecotourism hub. The main entry point into the Sinharaja reserve was previously another village, Kudawa. But growing awareness of the white monkeys meant an increase in tourists entering Lankagama, benefiting the local community. The WCSG also secured funding to build a culvert for the village and established the Sinharaja Base Camp, a research center inspired by these unique langurs.
Iconic color morphs
White animals have always attracted attention among humans, much like Canada’s spirit bears and Africa’s white lions. Like with Sri Lanka’s langurs, both are examples of leucism that have gone on to generate significant ecotourism revenue. De Silva says he believes Sri Lanka’s leucistic langurs hold similar potential.
A study published last year in the journal Human Ecology explores this issue, holding lessons for how these white monkeys can hold a unique status, even as the wider langur population is perceived as a group of crop-raiding pests. The research examined melanism (all black), albinism (all white) and leucism in four species often considered pests in the U.S.: coyotes (Canis latrans), eastern gray squirrels (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus) and black-tailed deer (O. hemionus).
The study highlighted how wildlife with distinctive coloration can be treated differently due to psychological and social factors, including the psychology of scarcity, folklore and personal interactions. The preferential treatment of such rare color morphs by humans could have significant implications for wildlife conservation, it says.
This phenomenon is particularly relevant for Sri Lanka’s white langurs, making them a crucial case study at a time when public resentment toward monkeys as nuisance animals is on the rise.
Omen animals
Reports of white monkeys in the forest of Sinharaja go back centuries, and elders in rural communities still recount sightings of pale-colored langurs. Robert Knox, a British sailor held captive in Sri Lanka during the 17th century, wrote about them in his 1681 book, An Historical Relation of the Island Ceylon. Though he didn’t specifically refer to white monkeys, he noted primates with unusual color variations, possibly early observations of leucistic individuals.
In The Natural History of Ceylon (1861), British naturalist James Emerson Tennent documented an instance of a white monkey being taken from Ambepussa and Kornegalle in Sabaragamuwa province, where they were said to be numerous. He observed that its striking whiteness might have suggested albinism, but its black eyes and face indicated otherwise.
The Sinharaja langurs are a population of the purple-faced langur’s southern subspecies, S. v. vetulus. There are three other known subspecies — northern, (S. v. philbricki), western (S. v. nestor), and mountain (S. v. monticola) — but the leucistic individuals have primarily been reported from the southern subspecies, according to de Silva.
Apart from leucistic langurs, there have also been rare occurrences of albino primates in Sri Lanka, including toque macaques (Macaca sinica), an endemic and highly conflict-prone species, and tufted gray langurs (Semnopithecus priam).
In Minneriya National Park, in the northwestern region of the island, observers spotted a white toque macaque with red eyes, indicating a case of albinism. Kithsiri B. Ranawana, a zoology professor at the University of Peradeniya, said the subadult macaque appeared weaker and stayed near its troop, likely due to poor camouflage and increased vulnerability.
Shashi Madhushanka, one of Ranawana’s students, later documented an albino gray langur, photographed in December 2015 in Yala National Park in Sri Lanka’s south. These discoveries resulted in a research paper published last year on Sri Lanka’s first documented cases of albino toque macaques and gray langurs.
A few years earlier, local naturalist Ajantha Palihawadana photographed an albino gray langur on two separate occasions, 17 months apart. The sightings may have been of the same monkey that matured into adulthood, or point to the possibility of a second albino individual living in the area. Either prospect, however, calls for more research, scientists say.
The presence of white monkeys across Sri Lanka — whether leucistic or albino — highlights the island country’s rich biodiversity and unique genetic variations. In Sinharaja, they’ve spurred ecotourism and conservation initiatives, emphasizing the importance of continued research and protection within this UNESCO World Heritage Site.
Banner image: An albino gray langur photographed in July 2014 at Yala National Park. Image by Ajantha Palihawadana.
Citations:
Roscoe, C. J., De Silva, M. A., Hapuarachchi, N. C., & Krishantha, P. R. (2013). A new color morph of the southern purple-faced langur (Semnopithecus vetulus vetulus) from the rainforests of southwestern Sri Lanka. Primate Conservation, 26(1), 115-124. doi:10.1896/052.026.0110
Madhushanka, S., & Ranawana, K. (2024). The first record of albino grey langur (Semnopithecus priam) from Katagamuwa, Yala National Park and endemic toque macaque (Macaca sinica) from Minneriya National Park in Sri Lanka. World News of Natural Sciences, 57, 34-38. Retrieved from https://psjd.icm.edu.pl/psjd/element/bwmeta1.element.psjd-5fe33759-a92e-416d-a2c5-c01f51511ede
Williams, T. D., Kreling, S. E., Stanton, L. A., Wilkinson, C. E., Estien, C. O., Schell, C. J., & Carlen, E. J. (2024). Of rarity and symbolism: Understanding human perceptions of charismatic color morphs. Human Ecology, 52(2), 461-474. doi:10.1007/s10745-024-00492-7
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