Tests have proven a long-held belief that Borneo's rare Sunda clouded leopard is really a different subspecies from its Indonesian relative, according to researchers.
The two subspecies of Sunda leopard -- which was only identified as a species in its own right in 2007 -- must now be managed differently, said a report by Andreas Wilting from the Leibniz Institute for Zoo and Wildlife Research and researchers from the Sabah wildlife and forestry departments.
"The Sunda clouded leopard in Borneo and Sumatra is a different species from clouded leopards across the Asian mainland," Wilting told AFP.
"We suspected the leopards on Borneo and Sumatra have likely been geographically separated since the last Ice Age, and we now know the long isolation has resulted in a split into separate subspecies," he added.
"The potential that they could evolve into full separate species, given that they are separate subspecies, means that captive breeders will now be better informed to keep the subspecies apart to allow them to evolve fully."
Wilting said that molecular analysis, genetic testing and skull morphology studies on fur and bone samples of the leopard from natural history museums worldwide showed the species followed different evolutionary paths.
The researchers say natural disasters were likely responsible for the split, with only two populations of the leopards in Borneo and southern China surviving the Toba volcanic eruption in Sumatra about 75,000 years ago.
"The ones on Borneo could have recolonised Sumatra via glacial land bridges and subsequently developed into a different subspecies as sea levels rose after the last Ice Age, isolating the two islands," said co-author Joerns Fickel.
Wilting said both subspecies are classified as endangered by the International Union for the Conservation of Nature because the big cats occur in small numbers and need big home ranges for their survival.
Researchers say the subspecies is the biggest predator on Borneo, a resource-rich island split between Malaysia and Indonesia where wildlife habitats are under pressure from logging and plantations.
Last February, researchers were able for the first time to capture the leopard on film at the Dermakot Forest Reserve on Borneo.
Explore further: First footage of clouded leopard captured in Borneo