Amazing images taken mainly by camera traps reveal a previously unrecognised species of macaque living in Tibet’s forests.
The photographs, also including some images from manually operated cameras, provide an intimate portrait of the cute primates – showing the monkeys grooming each other; foraging and tending to their young.
The elusive monkey, which researchers have called the white-cheeked macaque (Macaca leucogenys), had previously been identified as the Assamese macaque (Macaca assamensis).
But now researchers in China who took the images say the charismatic creature is a species in its own right.
Their analysis of hundreds of photographs and recordings of the monkey is published in the American Journal of Primatology.
“Using camera traps, we were just so lucky to capture some good photos of the white-cheeked macaque, which clearly showed characteristics of it and allowed us to claim it as a new species,” says corresponding author Dr Peng-Fei Fan from Dali University in the province of Yunnan, China.
In total, the team took 738 photos from camera traps attached to trees, and with manual cameras, in Medog county in Tibet.
The new species’ most distinctive morphological characteristic is its prominent white whiskers growing from its cheeks and chin, which inspired its new name.
White-cheeked macaques get their whiskers as they approach adulthood. These hairs grow longer with age, covering the ears of mature macaques, and giving them a round facial appearance.
Other distinguishing morphological features of the new species include thick hairs on its neck; a hairless, short tail, and round instead of arrow-shaped genitalia in males.
Another distinctive characteristic is its odd, high-pitched alarm call.
Research team member Cheng Li first noticed this unusual cry by chance back in 2012 when travelling in Medog county.
But it wasn’t until he had set up 31 camera traps as part of a wildlife survey that he got a clear look at the monkeys. Infrared motion detectors triggered the cameras to take photos and a 15-second video when an animal passed by.
On a separate trip, Dr Fan and colleague Chao Zhao had chanced upon the macaques by a river, and captured clear images of six individuals on ordinary cameras.
Analysis of the images suggested the existence of a macaque distinguished from all other described species in the Macaca genus.
“This discovery was a big surprise for all of us,” says Dr Fan.
He adds that, although other scientists might have noticed differences between the Assamese macaque and the white-cheeked macaque, there has not been solid evidence for its existence until now.
The photogenic white-whiskered monkey lives in diverse forest habitat, from tropical to high-altitude evergreen, broad-leaved and mixed broadleaf-conifer forest.
But the new species is already threatened by habitat destruction.
The team says its discovery highlights the need for more wildlife surveys and environmental protection in Tibet's forests.
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