Slow lorises are a group of primates belonging to the genus Nycticebus, closely related to lemurs. These creatures can be found across South East Asia – from Bangladesh and China’s Yunnan province to the island of Borneo. They are omnivores, eating insects, small birds, reptiles, eggs, fruits, nectar and other vegetation. 

They are recognized by their unique fur coloration on the body and face, yet while traits such as fur patterns are often used to distinguish between species; nocturnal species are cryptic in coloration and have less obvious external differences.

Slow lorises are rare amongst primates for having a toxic bite, and are rated as Vulnerable / Endangered on the IUCN Red List.

“Technological advances have improved our knowledge about the diversity of several nocturnal mammals,” said Ms Rachel Munds of the University of Missouri Columbia, lead author of the study published in the American Journal of Primatology.

“Historically many species went unrecognized as they were falsely lumped together as one species. While the number of recognized primate species has doubled in the past 25 years some nocturnal species remain hidden to science.”

The team focused on the distinctive colorings of Borneo’s slow loris, whose faces have an appearance of a mask, with the eyes being covered by distinct patches and their heads having varying shapes of caps on the top.