Zhang Fan
September 2009
Translated by Wong How Man

Buddhist pagoda marking entrance to Precious Bull Horn CaveOver lunch, I raised my glass to toast Mengyuan Village Chief Ayan, our host who is of Dai minority, after we completed exploring the cave. Four of us in our team started our exploration on August 29 soon after we arrived at the nature reserve of Xishuangbanna in southern Yunnan. In all, we explored a series of four caves to map and identify the biodiversity within these caves.

“Bao Niu Jiao Dong”, or Precious Bull Horn Cave, is the largest and took fully three days to explore. The other three caves took an additional three days. For the last few days, Ayan send two villagers each day to deliver food inside the cave for us. For us who lived in darkness all day long, such simple meal with rice and roast pork surpassed any banquet.

When the Chief heard that we had finished measuring the Bull Cave, he lowered his glass and spoke with urgent sincerity, “This cannot be. You must have neglected a very long side branch. Otherwise you cannot be this fast in finishing,” said the Chief. He caught me by surprise as I and Liu Hong have been exploring caves for almost twenty years without fail. Most caves we covered were far larger and more complicated than Bull Cave here.

CERS team preparing their equipment for explorationWhile there are chances of omission, but to explore a cave for three full days and were told we missed a large branch is a “first” and quite unthinkable. His claim made me felt embarrassed and wished that I was still inside a cave to hide my brushing.

I quickly called my teammates Liu Hong and Ah So together. They were in charge of mapping out the caves. Let’s scrutinize in our mind where we could have missed out with the many back and forth trips we made. Liu Hong brought out his notebook and searched to a page where he had noted down a sign of “?” upon it. “That could be the missing link as it was so small, barely one meter crack on the walls. Maybe that is the entrance to this side branch”, quipped Liu.

When he measured to that place, he simply pointed his flashlight inside and thought the crevice was too small to fit in thus abandoned climbing through it. Upon this discovery, we decided to move back inside the cave right after our meal.

CERS caver inside the cave in XishuangbannaSoon we were inside the cave and arrived at that particular turning point. It was indeed a very long branch. By the time we finished and exited the cave, it was already night time and outside the cave was almost as dark as inside.

Bao Niu Jiao Cave is a very matured cave, more so than we originally thought. Though the space is not too large, it is very well developed. The main cave is like the trunk of a tree with many side caves like branches growing out in all direction. While the main cave is only about one thousand meters in length, the branches add up to be more than twice the length. Thus the entire length of the cave is 3360 meters.

The temperature inside the cave is 21.2°C which is the mean temperature of the area, whereas humidity is between 80-97%. One can imagine how this microclimate compares with the outside temperature which is over 32°C, this cave is extremely comfortable in temperature and humidity. As usual, cave temperature and humidity remains the same throughout the day as well as throughout the four seasons of a year. It is indeed a most perfect climate device of nature. Though we did not measure the air quality inside the cave, the cleanness and crisp air was evident to all. In Europe, a cave with such quality air would already be utilized as a “medical cave”.

A cave cricket with extraordinarily long feelers for moving in darknessAt our official departure party, Mr Yang, head of the Xishuangbanna National Nature Reserve proudly introduced to us the huge biodiversity of the area. The vegetation coverage is most diverse in Yunnan and the province is often called “Botanical Kingdom” of China, whereas Xishuangbanna in the southern region of the province is compared to being the crown of this kingdom. This is where the very limited tropical rainforest of China is located. The Asiatic Elephant, the largest land mammal indigenous to Asia, also exist right here.

If one would identify Xishuangbanna on a model globe, it is right along the Tropic of Cancer. Spin that globe along its axis and you would see that in the world along this imaginary line which lies approximately 23.5° north of the equator are mainly dessert regions. Rainforest like Xishuangbanna along such latitude are few and far apart. For its uniqueness and immense value, Xishuangbanna is designated with a national level protected status.

For both China and the world, this is an important nature reserve. Many scientific researches have been conducted in the past. Published academic papers, books and manuscripts are like a mountain archive of material.

Cave map of Precious Bull Horn Cave prepared by CERS teamBut just as we finished exploring our caves here, we realized that our academic knowledge of Xishuangbanna, be it the zoological or botanical side, are very limited. This is because former studies and researches only focused on the “above ground” material. What lives in the darkness of the under world has never been explored or mentioned, creating a large void in our knowledge. This is just like how we missed out an important branch of the Bull Cave that we explored earlier, thus making our understanding of the cave incomplete. Prior to our visit, no one has conducted scientific study of the underground cave systems and its biological survey in Xishuangbanna.

In fact, such missing link in our knowledge is not only unique to Xishuangbanna. Throughout China, not one of our provinces or autonomous regions has made a more complete inventory of our own underground biodiversity wealth. It is generally believed by western scholars and scientists that biological forms within caves of the world should be between 50,000 to 100,000 species. An exhaustive study of six karst regions in the United States alone has yielded over 6,000 cave dwelling species.

In our exploration of only four caves in the Mengyuan area, we have collected 120 specimens of cave dwellers. Preliminary identification provided us with 26 different species, including both land and aquatic vertebrates and invertebrates. Out of these 26 species, initially we can only positively identify 13 of them, or a mere 50% of the total. The remaining half would likely reveal some species new to us and to science.

We are at the threshold a totally new world, an unknown world of darkness. It seems we should be proud of our pioneering work of caving in Xishuangbanna. But based on initial data we collected, there are at least 24 caves in Mengyuan alone and we have begun work on only four of them. Much lay ahead for us and future generation to complete.

As we lift this veil to a corner of darkness in this world, it also unveils a natural instinct of mankind, our curiosity to knowledge. After all, we represent the spirit of what we are known for, China Explorers.


Barely four months after the CERS team completed exploration of the Bao Niu Jiao Cave, situation changed dramatically. Just as the scientific report and cave maps are being finished, I visited Xishuangbanna during Chinese New Year in the last days of January.

As the New Year of the Ox came into being, I thought it most auspicious to pay a visit to a cave by its namesake, especially I was born in the Year of the Ox. As Zhang Fan noted to me, local Dai minority as well as those from across the national border pay pilgrimage to this cave as a tradition. This however may no longer be the case, at least not without a fee.

What was shocking was that the cave was closed with newly installed metal gate. Despite that it is considered within boundaries of a national nature reserve, the development rights have been assigned to some businessman from coastal Zhijiang Province. One caretaker told me that even the key to the cave has been taken away and no one would return until after the long Chinese New Year holidays.

In fact, the cave would be closed to the public until April when it would again reopen as a sightseeing attraction. Outside, construction of two buildings to house rolls of future shops were well underway. The entire landscape is going through a face-lift with the entrance to the area built like entering a gated amusement park. Multiple flag poles were planted as future visitors would look up toward the sky at this monumental entrance. The former natural and cultural dignity of a very unique place has all been transformed.

I fear the worst for this very special cave as its fate is now another example of ill-conceived development in pursuit of short-term financial gain. What we had in mind of contributing to exploration and conservation of our important natural and cultural heritage is again at stake! Has our discovery been a blessing or a curse for this wonderful cave? I think we the answer is carved on the huge metal name plate now presiding over the entrance to Bao Niu Jiao Cave.

Wong How Man