A Terrifying Time for Bats

A Terrifying Time for Bats
By Merlin Tuttle

The past month has seen a virtual explosion of premature speculation presented as though it were now proven fact, much of it traceable to a single article titled, “Bats are global reservoir for deadly coronaviruses,” that appeared in the June 14, 2017 issue of Nature. We’ve already issued a Bat Flash alert responding to this article, and to predecessors, all apparently part of a single cleverly planned campaign.

An adult male Straw-colored fruit bat (Eidolon helvum) from Kenya. This is the species first blamed for the “index case” of Ebola in the 2014 outbreak in West Africa. The species was soon exonerated. In fact, it is so resistant to Ebola that it is an unlikely source. Recent studies suggest a source other than bats.

Sensational speculation has become widely cited as fact1, with spin-off damage that will be exceedingly difficult to reverse. All who truly care about bats have cause to be deeply concerned.

Due to scary speculation attempting to link the SARS outbreak of 2002 to bats, bats have recently become central in the search for viruses2.  Thus, rapid advances in viral detection alone may have caused major bias. Also, the number of viruses found in bats is not necessarily indicative of risk.2 Many viruses are innocuous or even beneficial,3 including some that are closely related to deadly ones.4 Finally, the paper in question is based on models, and models are notorious for mistaken conclusions, regardless of the amount of data analyzed.5

A far more meaningful analysis should have considered the historic rarity of viral spillover from bats to humans. Many media stories now claim bats to be the primary source of so-called “emerging infectious diseases” like Ebola, though most of these speculations remain unproven.6- 7

Thai women collecting guano in Rakang Cave. These women spend countless thousands of hours sweeping up the guano and bagging it while being pooped on by hundreds of thousands of fruit- and insect-eating bats high overhead and report no ill effects.

Proponents of such speculation still cannot explain why hundreds of bat biologists, millions of people who eat bats, and the millions more who share cities with huge bat colonies are no less healthy than others. They can’t explain why bats artificially infected with Ebola haven’t become contagious or why virologists haven’t even been able to find live virus in the thousands of bats examined. Certainly, like all other mammals, bats must be capable of harboring at least a few dangerous viruses. Nevertheless, bats still have one of our planet’s finest records of living safely with humans.1

Children begin helping collect guano almost as soon as they can walk.
It seems that, if disease from bats was a serious threat, certainly these happy children, working in Thailand’s Khao Chong Phran Cave should have been short-lived! While taking these photos, I wasn’t protected from any of the so-called “emerging diseases,” nor have I been protected anywhere else, and over decades of time, I too have remained healthy.
I first met this 96-year-old guano-collector in Thailand’s Rakang Cave in 1981. When I returned 31 years later, Siri Tanomsri and his only slightly younger, also guano-collecting, wife remained in outstanding health despite decades of working in a bat cave. Such historic evidence simply doesn’t support recent speculation that exposure to bats is dangerous.

Michael Osterholm, director at the Center for Infectious Disease Research and Policy at the University of Minnesota, Twin Cities, notes that scientists should be careful to distinguish between what is possible and what is likely. He points out that rabies, for example, is widespread in bats and readily infects humans. However, “If that was enough for transmission we should all be dying of bat rabies in the U.S.” The virus can be transmitted only if an infected bat bites a human. That rarely happens, so transmission is rare.2

Tourists observing 1.5 million free-tailed bats emerge from the Congress Avenue Bridge in Austin, Texas. When these bats began moving into newly created crevices beneath this mid-town bridge, health officials warned they were rabid and dangerous. Yet, by simply posting small signs asking visitors not to handle the bats, no one has been harmed in more than 35 years of mutually beneficial coexistence.

Additionally, we must question why so many limited health resources are being diverted to some of the world’s rarest diseases. Even if we lump all these together (including SARS, MERS, Nipa, Hendra, Marburg and Ebola) they have caused fewer than 20,000 deaths in two decades.8 In contrast, dog-transmitted rabies alone kills 60,000 humans annually9 with hardly a ripple of comment. And even that is tiny compared to other sources of human mortality, such as obesity10, which are far easier to prevent.

The only logical explanation for such a skewed emphasis appears to be solicitation of hundreds of millions of dollars in grants11for otherwise difficult-to-justify research.1 The last campaign against bats centered on rabies, rendering bat conservation nearly impossible in the 1970’s, while huge profits went to rabies and pest control industries.12 This time the profits are going to virus hunters11 with even more potential for harming bats.

Anyone paying attention will see a regularly repeated strategy. Over and over, the most sensationally exaggerated stories cite the same virus hunting scientists and their organization.13-16 They present themselves as bat-loving conservationists, but it’s time to ask if perhaps they don’t love big grants a bit more than bats!

Their strategy is becoming quite clear. Begin with a sensational headline, followed by a few paragraphs of apparently supporting statements from similarly motivated scientists. Appear to be bat conservation-minded by often saying that it’s not the bats’ fault. It’s because we’re invading their territory. 11,13-16 Sometimes (far from consistent) ending with an admission that the speculation has yet to be proven, including qualifying statements that bats are valuable and should never be killed. Never mind abundant evidence that people don’t tolerate, and often kill, animals they fear, particularly if bats are believed to be disease-laden.12 

The famous bat colony in Austin, Texas, consumes tons of crop and yard pests nightly, attracts millions of tourist dollars annually, and has harmed no one. Learning to live harmoniously with bats promotes public health by maintaining a safer environment with fewer pesticides. For anyone who simply doesn’t handle bats, the odds of harm are too remote to measure.

As in the Nature example, most subsequent reports focus on the sensational beginning, often completely omitting the more moderate ending, exactly what a clever PR firm, attempting to foment fear of bats would advise. Unfortunately, it’s working like magic for scientists who know better. Their greed isn’t just harming bats. It’s also harming public health,1 and eventually will compromise the credibility of science in general at a time when it is most needed.

Currently, there is no better way to help bats than for readers to complain to publishers of irresponsible stories.  We have already addressed the original one in Nature, but the many subsequent publishers, who typically focused only on the worst elements, also should be contacted. We encourage you to continue sharing your opinions with them and thank you for your participation on behalf of bats thus far.




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Khao Chong Pran’s Bat Economics

Poachers were killing huge numbers of Khao Chong Phran’s bats and selling them to restaurants until guards were hired to protect the bats. In Thailand bats were killed for the restaurant trade before a law made it illegal.

The Buddhist temple at Khao Chong Phran is said to have been built largely from guano fertilizer sales. When Merlin first visited the site in 1981, monks were alarmed by a precipitous drop in guano production and asked his advice on the problem. He discovered that poachers were killing large numbers of bats by setting nets over the cave entrance late at night when the monks weren’t looking. The bats were sold to restaurants as a food delicacy. After Merlin convinced the monks to hire a guard in 1981, bat guano sales increased from $12,500 U.S. annually to $89,000 within 10 years, and by 2002, annual sales had reached $135,000 U.S.  Recently, the guano producing bats had been in gradual decline despite 24-hour protection by a team of four guards, so Merlin was quite pleased to discover several evenings ago that the most likely cause of renewed decline was simple to remedy–remove gradually encroaching vegetation.



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The Guano Miner’s Daughter

Push starting the Batmobile out of Khao Chong Pran

The Batmobile had to be “pushed” out of the parking lot of Khao Chong Pran. Dead battery. Once on the road again with a new battery, we were in search of another cave.

In January 1984, Merlin had written an article for the Smithsonian magazine about his trip to Thailand entitled “Harmless, highly beneficial, bats still get a bum rap.” In it he stated: “more than a million bats support an entire village of guano miners, but are about to be destroyed by an expanding limestone quarry. Some species might actually become extinct before they are discovered.” Thai conservationists, with Merlin’s help, got the quarry mining stopped in time to save the colony. On this trip, 30 years later, he wanted to check on the cave and see how the bats and villagers were doing.

The cave used to be near a military base. Now it was actually inside the base. P’Kwang, one of our BatThai guides, told the guard at the entrance we wished to go into Rakang Cave. The guard said we needed to get permission in advance to get into the cave and that it could take up to two weeks!

We drove past the quarry that Merlin remembered, and on to a nearby temple where we asked a   monk the whereabouts of the guano miners. He said the miners would not be working since it was a holiday.

We thought we’d try again with the guard at the entrance to the base, and as we approached we were excited to see a long line of cars going through the gate. We just,got in line and followed the others.  Now we had to find the cave, so we stopped at the golf course. P’Kwang spoke to some golfers, one of whom was a general, and he gave us permission to enter the cav e which was right across the road. What luck!

The cave’s entrance was as Merlin remembered. The ceiling was close to 70 feet high, and that’s where the bats were safely roosting. Daniel decided to climb a rickety, bamboo ladder used by the guano miners. One ladder was lashed to another up the cave wall toward the high ceiling. When he had climbed to the end of the third ladder, he saw a small group of bats roosting overhead and carefully stretched out with his long-handled net, catching two bats.

Daniel Hargreaves climbing toward the ceiling of Rakang Cave
Wrinkle-lipped Bat (Tadarida plicata)

Covered with bat sh*t, Daniel made it safely down the roach-covered ladder with the bats for Merlin to photograph.

As we exited the cave, got into the Batmobile and headed for Bangkok, Pongsanant, our BatThai guide and interpreter, was talking to a woman who had just arrived on a motorbike to mine guano. When he asked her if she knew of a man named Siri, she smiled and told him that he was her father. He was now 96 years old, but still in good health. She offered to take us to see him right away. When we arrived, his 81-year-old wife remembered Merlin’s having photographed her at the cave.

In the next blog I’ll tell you about the serendipitous visit with the guano mining family.


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Guano Happens

Covered with guano, Merlin  Tuttle and Daniel Hargreaves exit the cave

Merlin’s career in international bat conservation began at Khao Chong Pran Cave in 1982. During a trip funded by BCI’s founding trustee, Verne Read, Buddhist monks at the Wat Khao Chong Pran asked Merlin for help in discovering why the cave’s bats, whose guano they sold as fertilizer, were in severe decline.

Merlin meeting with the guards for Khao Chang Pran Cave

Aided by Thai assistant, Surapon Duangkhae–who latter became one of Thailand’s leading conservationists–Merlin discovered and documented that commercial bat hunters were catching many thousands of bats for sale to restaurants. His advice to the monks:  hire a guard to protect the bats from further exploitation. As a result, the colony recovered. The monks’ guano sales jumped from$12,000 USD in 1981 to $89,000USD in 1989, and $135,000 USD by 2002. Today there are three guards protecting the cave, and we were delighted to meet them. See Tuttle, Merlin D. (Fall 1990) Return to Thailand, Bats Magazine, volume 8, No. 3.


Meeting the head monk at Wat Khao Chong Pran

We also met with the head monk who remembered Merlin and his work at the cave.  He showed us the handwritten ledger of guano sales for the past two years, which will prove invaluable in evaluating the bats’ current status.  The monks don’t mine the guano themselves, they pay local villagers to do it.

The bats now additionally benefit the monastery by attracting thousands of bat watching tourists.






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