Skip to main content

Three New Slow Loris Species Discovered in Borneo; Rare Venomous Primates Threatened by Illegal Pet Trade

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Protecting the adorable but endangered slow loris—the world's only venomous primate—from the illegal pet trade suddenly got a little harder. According to a paper pending publication in the American Journal of Primatology, what was once recognized as one slow loris species and two subspecies is actually four different species.

Lead author Rachel Munds, an anthropology doctoral student at the University of Missouri, Columbia, (MU), says the loris's nocturnal nature and relatively similar appearance hid these species from science until the animals were examined more closely. "Historically, many species went unrecognized as they were falsely lumped together as one species," she said in a press release issued by Wiley, the journal's publisher. "While the number of recognized primate species has doubled in the past 25 years, some nocturnal species remain hidden to science."

In a separate press release from MU, Munds said, "Four separate species are harder to protect than one, since each species needs to maintain its population numbers and have sufficient forest habitat. Unfortunately, in addition to habitat loss to deforestation, there is a booming black market demand for the animals. They are sold as pets, used as props for tourist photos or dismembered for use in traditional Asian medicines."


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


The research team, which also included Oxford Brookes University anthropologist Anna Nekaris and Susan Ford from Southern Illinois University, looked at the slow loris's facial fur patterns, or facemasks, to make the new species declarations. "This finding will assist in conservation efforts for these enigmatic primates, although survey work in Borneo suggests the new species are either very difficult to locate or that their numbers may be quite small," Munds said.

Although their bite can be toxic, slow lorises are rather timid and easy to capture from the wild. As I wrote earlier this year, slow lorises are available in Indonesian markets for as little as $20, where they are stuffed into tiny cages after sellers rip out their front teeth and venomous elbow patches with pliers, nail clippers or wire cutters. Many of the animals die shortly after being sold, as the removal of their teeth can hamper their ability to eat and owners try to play with them during the day, disturbing their normal sleep patterns.

"The pet trade is a serious threat for slow lorises in Indonesia, and recognition of these new species raises issues regarding where to release confiscated Bornean slow lorises, as recognition by non-experts can be difficult," Nekaris said in the press release.

The entire slow loris genus (Nycticebus) is protected under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which bans international trade in the animals, although it still frequently occurs.

The new species identified by the study is N. kayan, which gets its name from the Kayan River that runs through its habitat in the central-east highland of Borneo. The authors describe the species as having a dark, highly contrasting facemask; a distinctive round or pointed patch; and longer, fluffier body hair than the Bornean slow loris (N. menagensis).

The scientists also say two previously recognized subspecies, N. m. bancanus and N.m. borneanus, should now be listed as species. The newly reclassified N. bancanus can be found in southwest Borneo and has a "distinct crimson red dorsal pelage." N. borneanus lives in the central-south part of the island and has a dark, contrasting facemask.

Previous research had suggested that Bornean slow lorises should not be considered separate species because their cranial morphology is similar. The new paper argues that "many small primates exhibit shared cranial features and therefore this may not be important when recognizing species."

Previously in Extinction Countdown:

Photo 1: Nycticebus kayan by Ch'ien C Lee. Photo 2: Slow lorises for sale in Möng La, Shan, Myanmar by Dan Bennett. Used with permission

John R. Platt is the editor of The Revelator. An award-winning environmental journalist, his work has appeared in Scientific American, Audubon, Motherboard, and numerous other magazines and publications. His "Extinction Countdown" column has run continuously since 2004 and has covered news and science related to more than 1,000 endangered species. John lives on the outskirts of Portland, Ore., where he finds himself surrounded by animals and cartoonists.

More by John R. Platt