From its origin in the Tibetan Plateau the Mekong River charges across country borders, supporting some of the most ecologically productive and important landscapes in the world. Flowing through China, Myanmar, Laos, Thailand, Cambodia and Vietnam the Mekong is the foundation for landscapes that harbor an extraordinary number of iconic species, including the Asian elephant, tiger, leopard, multiple species of pangolin,  ibises and freshwater dolphin.

The Mekong River alone holds 3 times more fish species per unit area than the Amazon River. In fact, an estimated 2.6 million tonnes of fish are harvested each year from its productive waters, making it the largest inland fishery in the world—up to 25% of the global freshwater catch. The region contains the largest combined tiger habitat in the world—540,000 km2 or roughly the size of France. Just in Myanmar and Thailand, the Dawna-Tenasserim Landscape  harbors one of the most extensive stretches of contiguous forest in Southeast Asia.

Each year, scientists are involved in the description and classification of new species found within the diverse landscapes of the Greater Mekong region. Some species are found after painstaking field work, with scientists sometimes spending months in the field collecting specimens. Some are found hiding in plain sight amongst populations of close evolutionary relatives and some are uncovered as previously unstudied specimens in museum collections. Each discovery process is one-of-a-kind, involving laborious database searches to ensure that it truly is a new species, detailed written descriptions of every minute detail of its characteristics, and nowadays, DNA analysis to look for distinctive markers.

In 2017 more species were discovered in Myanmar, Laos, Thailand, Cambodia and Vietnam than the 115 that were found in 2016. The 3 mammal, 23 fish, 14 amphibian, 26 reptile and 91 plant species discovered in 2017 bring the total count of new species discovered between 1997 and 2017 within the region to over 2,600. These incredible scientific achievements illustrate how little we know about the habitats and creatures the Mekong region supports, and emphasizes the potential for future discoveries.

Although the Greater Mekong region is considered a treasure trove of biodiversity, humans are placing immense pressure on the species already known, and those that have yet to be discovered. The development of roads, dams, agriculture, and mining are degrading and in some places, completely clearing away the habitats of endemic and globally threatened species. Poaching and snaring for the lucrative wildlife trade are also wreaking havoc on wildlife populations.

The discovery of 157 species in 2017 highlights the importance of conservation measures being carried out in Southeast Asia, and provides support for the increasing protection for wildlife and natural landscapes within the Greater Mekong region. Some of the newly discovered species are already at risk of extinction, and many have an insufficient amount of data to classify the status of their populations. However, with active conservation efforts we can ensure that stories of incredible discoveries, such as the ones illustrated here, can continue for years to come.

Skywalker Hoolock Gibbon: The First Gibbon Jedi Master

Myanmar

Discoverers: Peng-Fei Fan, Kai He, Xing Chen, Alejandra Ortiz, Bin Zhang, Chao Zhao, Yun-Qiao Li, Hai-Bo Zhang, Clare Kimock, Wen-Zhi Wang, Colin Groves, Samuel T. Turvey, Christian Roos,  Kristofer M. Helgen, Xue-Long Jiang

Just like Luke Skywalker’s long and difficult journey to become a Jedi master, the journey to confirm that the Skywalker Hoolock Gibbon was a new species took many years and a lot of hard work. The process began in 2007, 10 years before the discovery was published. Genetic evidence confirmed that H. tianxing diverged from H. leuconedys, their most closely related ancestor, about 0.6 million years ago.¹

According to Dr. Peng-Fei Fan of  Yat-sen University and Dali University in China, “it was a very long and slow process of discovery. There was no single moment [when] I realized that it was a new species, but I was very excited when I first knew the genetic results supported the morphological results. This is a big discovery for me and for the whole Chinese Primatological Society.”² Tianxing is the pinyin of the term heaven’s movement or skywalker, referring to the gibbons amazing ability to move through the forest canopy. The name also pays tribute to the scholarly history surrounding gibbons in China, which often regarded them as having noble or mystical characteristics.¹

The species has been listed as one of the 25 Most Endangered Primate Species in the world. There is little knowledge about the status of the Myanmar population although they are expected to occur in the Imawbum proposed National Park in Myanmar adjoining the Gaoligong Nature Reserve of China, and there are less than 150 individuals in China that occupy isolated habitats. Additionally, the species reproduction rate is low compared to other gibbon species, making populations vulnerable.^1,2 Dr. Fan created the NGO “Cloud Mountain” which works to educate locals, students, tourists, and the government about the species in the hope to facilitate its conservation and longevity in the wild.²

Hkakabo Razi Tube-nosed Bat: Lance Bass Bat

Myanmar

Discoverers: Pipat Soisook, Win Naing Thaw, Myint Kyaw, Sai Sein Lin Oo, Awatsaya Pimsai, Marcela Suarez-Rubio and Swen C. Renner

According to Dr. Pipat Soisook (Prince of Songkla University, Thailand), one of the scientists who helped discover Murina hkakaboraziensis, “I knew it right away, from the long golden hairs on the head and the back, that it [was] a new species.”²⁰ The same golden hairs that took Dr. Soisook by surprise have caused some to unofficially dub the species the ‘Lance Bass Bat’, after it’s likeness to the *NSYNC member’s iconic frosted tips.              

Everything about the discovery of M. hkakaboraziensis was exciting to Dr. Soisook and his colleagues. The researchers had not caught many other species of this genus the night before, and had little hope of catching anything on the chilly evening M. hkakaboraziensis was discovered. “My colleagues said they saw the bat flying and enter the net - if we came to check the net only a few minutes later the bat may not have been there!”²⁰

Dr. Soisook and his team are the only bat researchers to visit the sub-Himalayan habitat of the Hkakabo Razi forest, where M. hkakaboraziensis was discovered, since the 19th century. Although not much is understood about chiroptera diversity in the Hkakabo Razi forests, it is likely M. hkakaboraziensis is a very rare species, filling a very specific niche within its habitat.^20,21

Burning of grasslands for agriculture near the edge of the forest likely poses a significant threat to this species, and other bats within the area. Currently the Hkakabo Razi Landscape is being nominated by the Myanmar government as a World Natural Heritage Site, a designation that Dr. Soisook believes will “enhance the protection of the forest habitats and ensure the [continued] existence of these bats, and those yet to be discovered.”^20,21

Elfin Mountain Toad (English) / Cóc Núi Tiểu Yêu Tinh (Vietnamese): The Toad from Middle Earth

Vietnam

Discoverers: Nikolay A. Poyarkov Jr., Tang Van Duong, Nikolai L. Orlov, Svetlana S. Gogoleva, Anna B. Vassilieva, Luan Thanh Nguyen, Vu Dang Hoang Nguyen, Sang Ngoc Nguyen, Jing Che, Stephen Mahony

Asian mountain toads (Ophryophryne) are masters of camouflage, forcing researchers to rely solely on the male’s birdlike call when trudging through the forest in search of them. Dr. Nick Poyarkov of Lomonosov Moscow State University, Russia; Joint Russian-Vietnamese Tropical Research and Technological Center, Vietnam and his team spent hours at night collecting specimens at different elevations within the mountains of southern Vietnam. They were “surprised to see that the series we collected was quite diverse morphologically - some specimens were bigger and more robust. Those collected from higher elevations were much smaller and looked more slender.”²² After conducting DNA analysis and comparing their specimens with museum collections, they finally concluded that there were three different species they were dealing with - the smallest of which was not yet known to modern science.²³

Dr. Poyarkov and the team of scientists that discovered the new toad species named it elfina for two reasons: “First, it is very cute and indeed looks like a small elf or a leprechaun - a small funny-looking creature hiding in ferns and mosses.” The small “horns” on its upper eyelids have inspired some to liken it to a creature from Lord of the Rings. Second, “the new species occurs in a specific type of montane forest and can be found on mountain summits… it’s always foggy and very wet there, trees are small and curved and everything is covered with a thick layer of moss. Such forests are called ‘elfine forests.’”²²

Ophryophryne elfina can only survive in elfine forest habitats, typically above 1500 meters. However, some of the habitat the research team surveyed just four years ago has been totally destroyed. Deforestation within Longbian Plateau is therefore posing a serious threat to the integrity of elfina’s habitat and the population of this new species.^22,23

Salween River Basin Mud Snake

Myanmar

Discoverers: Evan S.H. Quah, L. Lee Grismer, Perry L. Wood Jr., Myint Kyaw Thura, Thaw Zin, Htet Kyaw, Ngwe Lwin, Marta S. Grismer and Matthew L. Murdoch

Dr. Evan Quah (Universiti Sains Malaysia, Malaysia) and his team were surprised to find a mud snake at all around the limestone caves and karst they were surveying. “As luck would have it, it turned out to be a new species, which made the experience even more thrilling and memorable for us.” Although the Homalopsidae family of snakes is well studied “only two species were [previously] known from the genus and they occur in a different watershed.”²⁴

The team only found one specimen of Gyiophis salweenensis, making it impossible to know the current status of the species. However, the persistent development of G. salweenensis’ habitat and the changing of agricultural practices within the area may mean that the species is already threatened.^24,25 Dr. Quah believes that his team’s “work has shown that the Salween River basin is an area rich in unrecognized diversity.” He is “confident that with more thorough surveys, many more species new to science remain to be discovered [here].”²⁴

Pancake catfish

Myanmar

Discoverers: Xiao-Yong Chen, Tao Qin, Zhi-Ying Chen

The discovery process of Oreoglanis hponkanensis was not an easy one. The habitat of Oreoglanis hponkanensis is located on a mountain in a very remote location, as the species prefers swift cold water.^26,27 Dr. Xiao-Yong Chen (Chinese Academy of Sciences, China) was a part of a team that discovered two new Oreoglanis species in 2007;²⁸ he says “[but] this discovery [of O. hponkanensis] expanded our understanding of this genus” even further.²⁶

Although O. hponkanensis is abundant at high altitudes within the Hponkanrazi wildlife sanctuary, it appears to be more rare than its relatives. Dr. Xiao-Yong Chen noted that “if Hponkanrazi keeps its status as a wildlife sanctuary right now, I don’t worry too much about [this species].” However, there is not much known about O. hponkanensis’ ecology and it is likely to be highly specialized to fast flowing rivers, making it vulnerable to environmental change in the future.²⁶

A New Bamboo Species from the Cardamom Mountains

Cambodia

Discoverers: Felix F. Merklinger, Phourin Chhang and K.M. Wong

The first Schizostachyum cambodianum specimen was collected from Cambodia in 2015, providing initial evidence that it was a new species. Two years later, after a second expedition to Cambodia and many careful investigations, it was confirmed that S. cambodianum was indeed something special and not yet known to science. S. cambodianum’s defining feature is an enlarged lobe at the base of its culm sheath - something that is relatively unique for bamboo species.^29,30  

According to Dr. Khoon Meng Wong (Singapore Botanic Gardens, National Parks Board, Singapore) “bamboos are some of the most difficult plants to study because many species, especially those in seasonal climates, do not regularly produce flowers needed for their diagnosis. This bamboo is very special because of the conspicuous basal lobe on the culm sheath and is the first of its kind known in Indo-China and Southeast Asia.” Although specimens were collected at multiple locations within the Cardamom Mountains, the bamboo appears to colonize disturbed habitat along roadsides making it vulnerable to roadside clearings.^29,30

Sam Roi Yot leaf-toed gecko (English) / Djing-djok din Sam Roi Yot (Thai) / Dixonius de Sam Roï Yot (French) / Samroiyot Blattfingergecko (German)

Thailand

Discoverers: Montri Sumontha, Nirut Chomngam, Eakarit Phanamphon, Parinya Pawangkhanant, Chutinton Viriyapanon, Wanlada Thanaprayotsak and Olivier S.G. Pauwels

Near Khao Sam Roi Yot, otherwise known as the “Mountain of Three Hundred Peaks,” a research team lead by Dr. Montri Sumontha stumbled upon a gecko population they had never encountered before. It was obvious from various morphological features that the limestone dwelling geckos were from the genus Dixonius, however the geckos extraordinarily unique color pattern was not characteristic of any of the Dixonius species known to science. Specifically, the two stripes running from the snout to the base of the tail allowed the team to identify the population as a scientific “novelty.”³¹

The Dixonius genus was originally carved out of the tree of life in 1997 when two new species were observed that did not fit into the existing gecko branches.³² Dixonius kawaseeki was discovered through an ongoing laborious review of the reptiles that call the Thai-Malay peninsula home.^31,33-36 Through the discovery team’s dedication, the identification of D. kaweesaki now brings the Dixonius genus to eight total species.³¹

According to current knowledge of D. kaweesaki, the species does not appear to be under any conservation threat. Although this seems to be promising for the species as a whole, D. kaweesaki is believed to be the second reptile species endemic to the Khao Sam Roi Yot massif and the third reptile species endemic to Thailand.³¹ It is therefore necessary to be conscious of potential threats to D. kaweesaki before any damage is done to the fragile ecosystem that has allowed it to thrive.

Reflections and Moving Forward

Evolution by natural selection has been at work throughout the 4 billion years since the first life on earth formed, resulting in the incredible diversity of species found in the Greater Mekong region. In contrast, Homo sapiens have only walked the earth for approximately 300,000 years and are now altering the biological landscape that evolution has built.³⁷ In fact, according to WWF’s most recent Living Planet Report, there has been a 60% decline in population size of the world’s wildlife in the last 44 years. An exploding human population and over-consumption has caused such large environmental changes that some scientists believe the world is entering a new human driven geological epoch dubbed the ‘Anthropocene’.

This unprecedented change has been due to the fact that as human population increases, so does the overall demand for environmental resources, resulting in run-away human consumption. In the Greater Mekong region, this consumption has led to a multi-million dollar wildlife trade industry. Within one of the largest intact dry forest habitats in Southeast Asia, the Eastern Plains Landscape of Cambodia and Vietnam, industrial-scale snaring and other forms of poaching has greatly reduced populations of flagship species including the tiger (now extinct in the landscape), leopard and dhole.

The markets of the Golden Triangle, where Thailand, Myanmar, Lao PDR, and China meet, play one of the largest roles in trading of illegal wildlife products internationally. Widespread consumption of wildlife products has driven up the prices of rare and endemic species, some of which may not even yet be documented by science. With the recent ivory ban in China, there is real concern and evidence that the trade will move to the neighbouring Greater Mekong countries of Cambodia, Myanmar, Laos, Thailand and Vietnam. Tourists from China travel in increasingly large numbers to all countries in the region and this opens up the possibility of increasing demand and trade in illegal wildlife products.

Consumption of energy, land, and water is also occurring at an alarmingly unsustainable rate. In the last 30 years, 30 percent of the forests within the Greater Mekong region have disappeared due to development. According to WWF’s Forest Pulse Report, the Greater Mekong has lost one third of its tree cover since the 1970’s and is predicted to lose another third between 2010 and 2030. This has created fragmented habitats with isolated populations, increasing the vulnerability of species to further disturbances. A road planned to cut across Myanmar’s dense Tanintharyi forests in order to connect the Dawei Special Economic Zone (SEZ) and deep sea port with markets across Southeast Asia and beyond would seriously disrupt movements of elephants, tigers and a host of other species inhabiting the landscape, many of them already endangered.

Elsewhere, the planned and ongoing construction of dams along the Mekong river creates serious threats to the largest annual movement of freshwater biomass in the world. WWF’s Living Planet Index showed a decline of 83% in populations of freshwater species worldwide since 1970. Out of the five specific biogeographical areas the LPI uses to categorize the world’s distinct groupings of species, the Indopacific region has the second largest biodiversity decline, with an 82% decline in populations of of freshwater species.  

Due to illegal wildlife trade,  forest loss and expanding human use of land through infrastructure development, many of the animals that have evolved over very long geological periods within the Greater Mekong may be gone just a few decades into the Anthropocene.

However, there is still hope to bend the curve of biodiversity decline in the five Greater Mekong countries. Governments, conservation organizations, and communities within the region are working together to conserve fauna and flora. In Myanmar, the government has banned all illegal wildlife trade products within the Yangon region -- a first for Southeast Asia. The Laos Prime Minister’s order No.5 instructs officials across Lao PDR to take strict action on wildlife law enforcement, comply with national laws, and make commitments to international laws on the management and inspection of wildlife trade. Enforcement actions have followed. Thailand’s law enforcement officers are arresting and prosecuting even very powerful poachers. In Vietnam, Hue City at the foothills of the Central Annamites is on its way to becoming Vietnam’s first “Wildlife Meat-Free City.”

Overall, the conditions for bending the curve for wildlife populations are improving but sustained action is essential. Despite the incredible challenges humans place on wildlife, some populations within the Greater Mekong do show hope of bouncing back after extreme population declines. The population of Irrawaddy river dolphins in the Cambodia stretch of Mekong has increased for the first time in over two decades and now stand at 92 individuals. This is thanks to relentless patrolling of rivers in search of illegal fishing activities and confiscation of gillnets. Additionally, one of the most threatened land-dwelling mammal species in Southeast Asia, the large-antlered Muntjac, was recorded for the first time in Quang Nam province, Vietnam.

Thailand remains a stronghold of tigers and Asian elephants thanks to an impressive national parks system and a commitment to rangers. And it has strengthened legislation on the ivory trade, although an outright ban on domestic ivory sales is still elusive.

WWF’s 2018 Living Planet Report emphasizes that in order to reverse the decline in biodiversity characteristic of the Anthropocene, the world needs to take drastic actions. Although many conservation measures are currently in place and reaping fantastic rewards, it’s clear that much more needs to be done.

“There are many more species out there waiting to be discovered and tragically, many more that will be lost before that happens,” says Stuart Chapman, WWF’s Asia-Pacific Regional Director for Conservation Impact. “It doesn’t have to be this way.  Ensuring that large reserves are designated for wildlife with adequately equipped and trained rangers -- along with increased efforts to close illegal wildlife trade markets -- will go a long way to conserving the extraordinary wildlife diversity in the Mekong region.”