A female adult white-cheeked macaque (top) and three juveniles are photographed in Medog county in the Tibet autonomous region. [Photos by Li Cheng / for China Daily]

Chinese scientists say they have discovered the world's newest monkey species

Chance, or "luck", has played an important role in many breakthrough scientific discoveries, and Lady Fortune was up to her old tricks again recently as she helped produce one of the country's most important zoological discoveries of the decade — the world's newest monkey.

The "lucky" discoverers of the white-cheeked macaque are Li Cheng, an amateur naturalist and wildlife photographer based in Shenzhen, Guangdong province, Fan Pengfei, one of China's leading primatologists who works at Dali University in Yunnan province, and his colleague Zhao Chao, who is also a dedicated wildlife photographer.

In November, Fan, Zhao, and ornithologists Liu Yang and Liang Bin traveled extensively from northwestern Yunnan province to the southeastern part of the Tibet autonomous region.

The area they explored is located at the junction of the Eastern Himalaya and the Indo-Burma region, a noted biodiversity hotspot and considered a frontier for biological discoveries.

On their journey from Dali to Bayi, the major town in Nyingchi prefecture, the men encountered a family of pilgrims headed for Lhasa, who they greeted and supplied with food.

At the end of the first leg of the journey, the ornithologists headed home, while Fan and Zhao drove on to Modog county. On Nov 18, they saw the family again on the Sichuan-Tibet Highway, which runs alongside a major tributary of the Yarlung-Tsangpo River.

The father of the family pointed to the forest on the other side of the river, indicating that he'd seen something unusual. Using his binoculars, Fan quickly identified the objects of interest — monkeys — and as he observed the group, Zhao quickly began snapping photos of the family of six, consisting of two males and four females. They were grooming each other, foraging and sporting on the riverbank. After a while, a couple began mating.

"We knew they were a kind of macaque, but couldn't identify the species in the field," Zhao said, when he spoke to China Daily.

"So we just observed, took videos and photos. It never crossed our minds that we had discovered a new monkey."

However, when Fan and Zhao attempted to identify the monkeys back at their university, they quickly realized they were not Assam macaques or Tibetan macaques.

While comparing their photos with those published by Indian researchers featuring the Arunachal macaque, which was described and accepted as a new species in 2005, they found the two "looked quite different. Then we started taking the encounter seriously," Zhao said.

A little later, a zoologist friend introduced Fan to Li Cheng, an amateur naturalist who had hundreds of photos of an "unidentified" monkey taken in Modog county in Nyingchi, close to the spot where Fan and Zhao had seen their mysterious monkeys.

In 2012, Li had started exploring the wilderness of Modog — the last county in China to be linked to the outside world, via a highway that opened in 2013. It had been virtually cut off from the rest of the country, and was one of the least-visited wildlife havens in the nation.

While traveling in Modog in 2012, Li heard an unusual monkey call, but was unable to catch a glimpse of the animal. "It was an extremely high-pitched call that could be heard 1 or 2 kilometers away," said the 31-year-old climber and ardent explorer.

In October 2013, Li returned and set up 31 camera traps in the unspoiled, primitive forests as part of a wildlife survey organized by the Forest Survey and Planning Institute of the Tibet autonomous region and the Imaging Biodiversity Expedition, a grassroots organization in Beijing that aims to record China's natural world through images, such as photographs and videos. Li joined the IBE in 2013.

Eventually he managed to take some photos of the monkey. "It made the same odd alarm call," he said. "It's truly recognizable."

Triggered by infrared motion detectors, the cameras took three photos and a 15-second video whenever an animal passed by.

In April 2014, Li returned to Modog to recover the cameras and harvested more than 600 photos and 100 video clips of the monkey.

"I was thinking it might be a new species. But until I got in contact with Dr Fan, I didn't know that these images were truly crucial evidence of a new discovery," he said.

After studying all of the materials, Fan, Li and Zhao were almost certain that they had discovered a new species of primate.

Fan and Zhao were unable to avoid the thought that researchers from other countries might also be working to identify the new species. "We were a little paranoid," Fan said. "But it's normal, especially when you consider that we Chinese scientists have missed quite a few primate discoveries."

China is home to 24 species of primate, but only one — the White-headed Langur — was first described by Chinese scientists, according to Fan.

The Myanmar snub-nosed monkey was described in 2010 in northern Myanmar. "In 2011, we found the monkey was also living in our country," he said.

The eastern black-crested gibbon is a species from southeast China and North Vietnam, but there had been no confirmed sightings since the 1960s, and it was thought to be possibly extinct. Then, in 2002, a small population was discovered in northeastern Vietnam. "We were four years late finding it in China," he said.

Time was of the essence. "We certainly had a sense of urgency to have our findings published as soon as possible," Zhao said.

"That's why we decided to leave collecting and analyzing DNA samples of the monkey to the next stage of our research."

There were other considerations too.

"It's totally acceptable to describe an animal species based completely on image materials in academic circles," Fan explained.

They finished and sent out their research in January, leading the American Journal of Primatology, a monthly peer-reviewed science journal, to publish their analysis of hundreds of photographs and recordings of the new monkey in Jan 23. The journal confirmed the charismatic creature as a species in its own right.

"The white-cheeked macaque was the second macaque species described by scientists in the last 100 years," Li Baoguo, president of the Chinese Primatological Society, told Xinhua News Agency.

"The discovery is very important to our scientific research into the human impact on the shift of biodiversity, especially the distribution and evolution of species."

chenliang@chinadaily.com.cn