The Popa langur with darker gray fur on its back and arms and lighter gray fur on its chest is sat in a tree surrounded by branches and green leaves. It is staring directly at the camera.

There are thought to be only around 200-250 individual Popa langurs left, meaning they are already considered critically endangered ©Thaung Win

New species of monkey is already critically endangered

A new species of monkey living on an extinct volcano in Myanmar has been described for the first time.

Mount Popa, where the newly named Popa langur monkeys live, is a sacred pilgrimage site and home to Myanmar's most venerated spirits. It is now also home to the largest population of the critically endangered monkeys.  

The skin and skull of a monkey collected in Myanmar over 100 years ago has helped researchers describe a new species primate.

A team of international researchers were able to determine that a skin that had been in the Museum's collections for over a century belonged to otherwise undescribed species of monkey. They looked at its fur colouration and bones, and sampled its genetics to compare with closely related species.

Now named the Popa langur (Trachypithecus popa), the monkey joins the other 512 known species of primates that live around the world.   

Roberto Portela Miguez is the Senior Curator in Charge of Mammals at the Museum, and was involved in describing the new species, published in the journal Zoological Research.

'Monkeys are one of the most iconic groups of mammals, and these specimens have been in the collections for over a hundred years,' explains Roberto. 'But we didn't have the tools or the expertise to do this work before.

'It is thanks to this collaboration with multiple international colleagues and latest sequencing techniques that we manage to bring this species to light'

The skull of a Popa langur is pictured from three different angles on a black background. The first, shows the skull from the top down, the send side on, and the third from the bottom up.

There are a few distinctive parts of the Popa langur's skull, including larger molars and an more elongated skull © Kevin Webb/Trustees of the Natural History Museum, London

Roberto's colleague, Christian Roos, is from the German Primate Centre at the Leibniz Institute for Primates and led the research. He was trying to figure out the evolutionary relationships between a particular group of langur monkeys in the genus Trachypithecus.

It was during this research that it seemed one species was far more diverse than initially thought, and it was this trail that eventually led Christian to the Museum.

When one species becomes three

Phayre's langur, also known as Phayre's leaf monkey, has been found right across Southeast Asia, from India through to China and down into Laos and Vietnam.

It is this wide distribution, across mountains and rivers, that may have hinted that a population in central Myanmar was not quite the same species. It has long been thought that there were at least two subspecies, meaning that while they were different from each other, they were not quite different enough to be designated their own species.   

But after conducting genetic studies the researchers found that these two subspecies were distinct enough to be considered actual species.

By looking in intense detail at the appearance of their skins and skulls, the team also discovered that a third population of the monkeys, living on an extinct volcano called Mount Popa in Myanmar, were also different enough to be considered a third species.

This third species has been named the Popa langur after the mountain on which they are found.  

At the top of the image the skin of a Popa langur lies face down with its front legs extended forward and back legs backward, show it's gray and white fur. Below this, the same skin is pictured on its left-hand side, with its head and forearms pointing towards the left.

The specimens of the newly described Popa langur held at the Museum were first collected in 1913 © Kevin Webb/Trustees of the Natural History Museum, London

Christian says, 'The DNA analysis of a museum specimen collected for the London Natural History Museum more than 100 years ago has finally led to the description of this new species, confirmed also by samples collected from the field by Flora & Fauna International's research team.'

The researchers admit that physical differences are subtle, meaning that it took the combination of the genetics, museum specimens and the distribution of the animals to determine that they were a new species.

'It could be difficult for anybody in the field to be able to tell this is a different species from the others,' says Roberto. 'There are small differences, so you need to know what to look for.

'If you have access to museum specimens, one is the larger size of molars and the skull is a bit more elongated in the Popa langur. There are also some physical differences in the skins, but the colouration is quite variable within and across these species.

'But generally you can see that the blackness in the lower arms of the Popa langur seems to extend slightly above the elbow, while in the other species it seems to be limited to below the elbows. The white muzzle is also wider in Popa and their eye are always fully encircled with broad white eye-rings.'

This research was only made possible by the collaboration between the German Primate Centre, the conservation organisation Fauna & Flora International, who were able to actually go out into the field to collect fresh samples of DNA in the form of poo from the newly described species, and natural history collections such as the Museum.

Popa langur already on the brink

Phayre's langur was already considered endangered due to hunting and habitat loss. With the species now split into three, each new subspecies is also considered endangered, with the Popa langur critically so.

'The new species is critically endangered because its numbers are phenomenally low,' explains Roberto. 'There are about four different populations, with the most viable population of the Popa langur containing just over a hundred individuals.

'In total across the five populations we estimate between just 200 to 260 animals left.'

A small town is nestled among a lush, green forest. Directly behind the buildings rises the huge stone outcrop of Mount Popa where the Popa langur lives, topped with the golden spires of a temple.

Mount Popa is home to Myanmar's most venerated spirits known as 'Nats', and now also protects the largest population of Popa langurs © Alexis/Flickr CC BY-NC-ND 2.0

Myanmar is a fast-developing country. Over recent decades, there has been a lot of international investment into the nation, which has spurred on the growth of industry and road building. This has led to not only an increase in the destruction of forest habitat but also an increase in hunting that these activities invariably bring.

The one good thing, however, is that that largest population of Popa langurs is found within an already protected area.

'We hope that the naming of the species will help in its conservation,' says Roberto. 'The hope is that by giving this species the scientific status and notoriety it merits, there will be even more concerted efforts in protecting this area and the few other remaining populations.

'At least whatever decisions are made in the future when it comes to things like how the parks are managed, those be from a more informed point of view as we now know of the distinctiveness of the population of langurs that is actually there.'

With this larger population still living on the sacred Mount Popa, there is a glimmer of hope for their future.

Ngwe Lwin, a primatologist with Flora & Fauna International's Myanmar program, adds, 'Additional field surveys and protection measures are urgently required and will be conducted by FFI and others to save the langurs from extinction.'