Severe Weather Takes Heavy Toll in Texas

By Merlin Tuttle
3/2/21

Given overall warming trends, we weren’t surprised to see some 70 to 80° F days in January and February of 2021. But that hardly tells the full story!

Beginning on February 10th, historically low temperatures were recorded across Texas. For eight consecutive days (February 10–18), the temperature hovered between 37° and 9° F with six inches of snow on the ground in Austin, Texas. The first reasonable feeding opportunity for bats likely didn’t occur before the 21st.

The last similar event occurred 32 years ago in 1989. In a 9-day period (December 16–24) the daily temperature ranged from 51 to 4° F but remained below freezing for only two days versus seven in 2021. Fewer people were concerned in those days, but at least hundreds of killed bats were reported.

Brazilian free-tailed bats about to emerge from their day roost in a bridge crevice in Austin, Texas.

The recent event, Winter Storm Uri, created a disaster for overwintering Brazilian free-tailed bats (Tadarida brasiliensis). Encouraged by warming trends, more and more bats have remained in their summer roosts year-round instead of migrating south for winter. In recent years, hundreds of thousands have overwintered in bridge crevices of Central Texas, especially in the Austin area. Additionally, over the last four decades, an estimated 1,000 more annually have remained in Bracken Cave.

Unlike many other temperate-zone bats, Austin’s free-tails are not true hibernators. They do store fat in the fall and can survive for more than six weeks without feeding when roosting at 41° F. In Central Texas, they emerge and successfully feed when evening temperatures are 50° F or above, and in traditional winters they seldom would need to wait more than 10 days between feedings.

To survive for eight days with average temperatures well below freezing would be an extreme challenge. Bats have the largest surface area per volume of any warm-blooded animal, and active free-tails maintain body temperatures of roughly 102° F. Following the recent weather crisis, just warming up to go hunting was undoubtedly prohibitive for many, and it’s difficult to imagine that the insects the bats depend on for food would have been immediately abundant. Even though daytime temperatures averaged 78° F over four consecutive days beginning on February 21st.

Many concerned Austinites wondered why accumulations of dead and dying bats steadily grew through at least the 25th, despite the return to warm weather. The answer is two-fold. Many bats likely were still alive but too weakened to go hunting. Some of those may take a week or more to die. Also, those that literally froze to death could take weeks to fall from their roosting crevices. Tendons in their toes are designed to automatically lock the bats’ claws firmly to the roosting crevice until consciously released. Thus, a bat may hang in place long after its death

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Bat Flash! Help Last Week Tonight Put Bats in Perspective

The Last Week Tonight with John Oliver February 15th episode shared misguided speculations about bats. Here is Merlin’s public letter to John Oliver. We don’t have his email address, so we’re counting on you to help get his attention. No shade, John, we understand the topic is muddy. We simply want the opportunity to set the record straight!

Contact information and action steps are listed below.

Dear John,

Given your reputation for integrity and fearless candor, several of your loyal followers have asked me to help you better understand disease risks from bats. Why me? Because, as one of the world’s most experienced bat researchers, I’ve handled hundreds of species worldwide for 60 years, often surrounded by millions in caves. I’ve also led successful conservation efforts internationally for more than 40 years. My experience and photographs are used worldwide, including in National Geographic articles, to share the truth about bats through my organization, Merlin Tuttle’s Bat Conservation. Here’s a clip from my appearance on David Letterman decades ago; I have been leading efforts to educate humans about bats my entire career.

I, and hundreds of others who study bats, have spent whole careers working with them unprotected against any of the so-called emerging diseases about which we’re now warned. And we’re still healthy. We’re also aware that millions of people visit and work in caves annually without causing disease outbreaks.

Thus, we question the sanity of warnings of extreme risks to visitors of tour caves where a bat could purportedly cause a deadly pandemic by defecating on them. There is no proof that such an event has ever occurred. And warning of the possibility is like warning of death from a falling spacecraft, possible but extremely unlikely.

I appreciate your mention of the far greater risks from industrial meat production and your comments on the essential contributions of bats to a healthy planet, but this is not enough to cultivate understanding and put risks in perspective. For the record, unlike rodents who are overpopulating due to the loss of predators, bats are extraordinarily vulnerable to extinction and already in alarming decline.

Exaggerated fear is the greatest cause of human intolerance and killing of bats. Unfortunately, sensational speculation, linking them to scary diseases, sells headline media stories and large grants. Virus hunting, typically linked to bats, has been shown to be an ineffective means of pandemic prevention. However, because bats are the easiest mammals to sample, and have few defenders, they have become tempting victims. Your guest failed to mention that, for anyone who simply doesn’t handle bats, the risk of contracting any disease from one is minuscule. In fact, millions of bats share cities with people from America to Africa and Australia without causing disease outbreaks. As our human population continues to expand, we inescapably must learn to live in harmony with nature.

Although well-intended, the following documented points are too often distorted or ignored in sensational media coverage. I’d be more than happy to assist you and your staff in balancing the story.

  • Bats harbor no more viruses than other animals 1.
  • Claims of disease from bats are often based on poorly supported speculation 2.
  • Claims of 96% genomic similarity between viruses are meaningless and misleading 3,4.
  • Promises that can’t be kept are misdirecting billions of dollars to virus hunting that is counterproductively biased toward bats and better spent on other health priorities 5,6, 7.
  • Bats have an undeniable history of living with humans without causing disease outbreaks 8.
  • There is a long history of lucrative, but exceptionally harmful, exploitation of disease exaggerations against bats 9.
  • Fear of bats leads to intolerance and killing 9,10.
  • Asking people to conserve bats because they are beneficial, while failing to counter exaggerated fear, is unlikely to improve conservation success 10.
  • Ebola was first speculated to come from fruit bats, then insectivorous bats, but more recently it was admitted that no source has been found despite extensive efforts 11, 12.
  • It cannot be stated strongly enough that Ebola, SARS, MERS, and SARS-CoV-2 have not been isolated from a bat despite frequent attempts.

Also, here’s a recent video sponsored by the U.S. National Park Service about putting bat fears in perspective. Thank you for your time, I hope to hear from you.

Kindly, 

Merlin

TAKE ACTION!

Our combined voices can make a difference. We encourage you to invite John to discuss the truth about bats with Merlin and politely share your opinion in your own words via social media. You may find our resources, Give Bats a Break and Good Intentions Can Still Leave a Bad Taste, additionally helpful in composing your personal reply and discussing these topics with others.

It’s numbers that count and bats need all of you! Tell a friend about bat values and how they can help.

Millions of visitors have safely viewed spectacular emergences of 1.5 million bats in Austin, Texas.

References

  1. Mollentze, N. & Streicker, D. G. Viral zoonotic risk is homogenous among taxonomic orders of mammalian and avian reservoir hosts. Proceedings of the National Academy of Sciences of the United States of America (2020) doi:10.1073/pnas.1919176117.
  2. Wenzel, J. Origins of SARS‐CoV‐1 and SARS‐CoV‐2 are often poorly explored in leading publications. Cladistics cla.12425 (2020) doi:10.1111/cla.12425.
  3. Mallapaty, S. Coronaviruses Closely Related to the Pandemic Discovered in Japan and Cambodia. Nature 588, 15–16 (2020).
  4. Mikkelsen, T. S. et al. Initial sequence of the chimpanzee genome and comparison with the human genome. Nature 437, 69–87 (2005).
  5. Holmes, E. C., Rambaut, A. & Andersen, K. G. Pandemics: Spend on surveillance, not prediction. Nature 558, 180–182 (2018).
  6. Zhang, Y.-Z. & Holmes, E. C. A Genomic Perspective on the Origin and Emergence of SARS-CoV-2. Cell (2020) doi:10.1016/j.cell.2020.03.035.
  7. Tuttle, M.D. A Viral Witch Hunt. Issues in Science and Technology. (2020) https://issues.org/a-viral-witch-hunt-bats/.
  8. Taylor, M. Bats: An Illustrated Guide to All Species. (Smithsonian Books, 2018).
  9. Tuttle, M. D. Fear of Bats and its Consequences. Journal of Bat Research & Conservation 10, (2017).
  10. Lu, M. et al. Does public fear that bats spread COVID-19 jeopardize bat conservation? Biological Conservation 108952 (2021) doi:10.1016/j.biocon.2021.108952.
  11. Marí Saéz, A. et al. Investigating the zoonotic origin of the West African Ebola epidemic. EMBO Molecular Medicine 7, 17–23. (2015) doi:10.15252/emmm.201404792
  12. Kock, R.A. et al. Searching for the source of Ebola: the elusive factors driving its spillover into humans during the West African outbreak of 2013-2016. Revue Scientifique et Technique (2019) doi:10.20506/rst.issue.38.1.2937.

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Bat Flash! Where Did COVID-19 Really Come From?

01/28/21

By Merlin Tuttle

USA Today’s January 17 story, Where did Covid-19 come from? leads with the following statement “The coronavirus that conquered the world came from a thumb-sized bat tucked inside a remote Chinese cave. Of this much, scientists are convinced.”

Deep in the story, they quote virologist John Connor at Boston University, saying ‘It looks like it’s a bat-derived virus, and there’s a big question mark after that.’ Fellow virologist, Charles Chiu, an expert in viral genomics at the University of California—San Francisco, is additionally quoted as saying ‘It may also have emerged from any setting in which people come into contact with animals, including farms, pets or zoos.’

Clearly, all scientists are not convinced that this virus came from bats, not even those interviewed for this story. The disproportionate focus on bats as the source of the COVID-19 pandemic is based on poorly supported speculation that harms conservation efforts worldwide.

Intermediate Horseshoe Bat (Rhinolophus affinis)

One of the most cited studies accuses bats of hosting more viruses than other mammals. Yet, the authors of this study surveyed twice as many bats as all other mammals combined. More inclusive research suggests that bats do not harbor more viruses than other animals.

New viruses can be found wherever we look, so it is not surprising to find more in the animals that are predominately searched. The claim that the SARS-CoV-2 virus, the source of the COVID-19 pandemic, shares 96% of its genetic material with a coronavirus found in a horseshoe bat is meaningless. We ourselves are 96% genetically similar to chimpanzees which we easily recognize as non-human.

Current biases threaten the survival of bats that have undisputed value and are already in alarming decline. They also harm science credibility and misdirect the search for zoonotic reservoirs by focusing disproportionately on bats. Despite relentless searching and endless speculation, there is no documentation that SARS-CoV-2, SARS, MERS, or Ebola viruses have been found in, or transmitted from a bat to a human.

As noted by Yong-Zhen Zhang and Edward Holmes, it is critical that coronavirus surveillance should include animals other than bats. Blaming bats based on one-sided searches is premature and misleading.

 TAKE ACTION!

Our combined voices can make a difference. We invite you to politely share your opinion in your own words with the editors. You may find our resources, Give Bats a Break and Good Intentions Can Still Leave a Bad Taste, additionally helpful in composing your personal reply and discussing these topics with others. Editors do take notice. Remember, your response can be very simple such as, “I don’t appreciate misleading speculation that perpetuates needless fear of bats.” Editors just need to know you like or dislike an article for you to have an impact.

It’s numbers that count and bats need all of you! Tell a friend about bat values and how they can help.

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Bat Flash! NatGeo’s “Virus Hunters” Spreads Groundless Claims About Bats

11/2/2020

By Merlin Tuttle

I viewed the National Geographic documentary series titled, “Virus Hunters,” with substantial disappointment. Warnings of growing reliance on bush meat and industrial farming were justified. However, coverage of wildlife too often exaggerated risks from bats. 

Bats are exceptionally easy to trap in large numbers, have few defenders, and are easily misunderstood. This makes them prime targets for scary speculation that is exceptionally lucrative in gaining media readership and unprecedentedly large grants. And unfortunately, the opinions of leading virologists who doubt that virus hunters can predict or prevent pandemics were left unmentioned.

The 2017 study that reported more viruses in bats than in other mammals sampled nearly twice as many bats as all other mammalian orders combined. Since most viruses have yet to be discovered, new ones can be found wherever we look. And because bats are an ancient group of mammals, it is not surprising that they sometimes host ancestors of modern species. 2020 study, concluding that bats harbor no more viruses than other animals, has been largely ignored.

Hundreds of thousands of Straw-colored fruit bats (Eidolon helvum) beginning their evening departure from a city park in Ivory Coast, Africa. Cities often provide the only homes safe from commercial hunters who sell them for people to eat. Despite such large numbers having lived in close association with humans throughout recorded history, they have not caused disease outbreaks. Their remarkable safety record casts grave doubt on recent speculation of their being dangerous carriers of disease.

Documented transmission of any disease from a bat to a human is exceedingly rare, and the risk is near zero for anyone who simply does not handle them. Hundreds of thousands of bats live in city parks across Africa. Yet there are no verified cases of Ebola transmission, despite huge efforts to find such an association. In fact, despite repeated assertions, there are no documented cases of Ebola, MERS, or SARS-CoV-2 viruses ever having been found in a bat, much less transmitted from a bat to a human. In truth, bats have one of the world’s finest records of living safely with humans. For example, in Austin, Texas countless thousands of visitors have safely viewed the spectacular emergences of 1.5 million free-tailed bats for decades without a single incident of disease transmission.

I have safely studied bats for more than 60 years, including publishing five articles in their defense in National Geographic. It is sad indeed to see bat survival threatened due to the same, traditionally respected, organization spreading groundless claims that bats can defecate deadly viruses by simply flying overhead. People seldom tolerate and often kill animals they fear, and none are more vulnerable than bats. Please, in your future coverage of Virus Hunters, put bat risks and benefits in perspective. The irresponsible spreading of falsehoods needs to stop.

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Bat Flash! Unveiling the Real World of Bats in a Time of Misinformation

9/15/2020

By Danielle Cordani

The avalanche of speculative reports associating bats with COVID-19 seems never ending. However, at a time of scary misinformation, bat researchers and conservationists worldwide are discovering new reasons to appreciate bats, some decades in the making.

In Central America, researchers from the Free University of Berlin analyzed communication between bat mothers and their pups. Just like humans talking to a baby, adult greater sac-winged bats (Saccopteryx bilineata) alter the “color” and pitch of their pup-directed vocalizations. Not surprising, this breakthrough indicates parent-offspring communication in bats is more complex than previously assumed. Further investigation of social feedback during vocal development in young bats may reveal even more shared language features between bats and humans.

A greater sac-winged bat (Saccopteryx bilineata) in Panama.

Across the Atlantic, a team of scientists in Africa used novel methods to describe more accurately the differences among bats. It turns out—as is common when studying bats—there is more than meets the eye. Comparison of the penis bones, echolocation calls, and genes of African vesper bats revealed three new species and two new genera. The discovery could mean new identification techniques for the often-indistinguishable group and clearer protections for unique bats and their ecosystems.

A banana pipistrelle (Afronycteris nana), showing its tiny size and one of its adhesive pads used for clinging to the inside of unfurling leaves.
Banana pipistrelles roosting in an unfurling banana leaf in Kenya.
Perhaps the most publicized bat discovery of 2020 was conducted by a group of scientists from Israel. Their groundbreaking study presents never-before-seen evidence of “cognitive mapping” in non-human animals. Using revolutionary tracking technology, Egyptian fruit bats (Rousettus aegyptiacus) proved extremely sophisticated and efficient at navigation. Bats relied on goal-directed memory maps rather than landmark cues or sense of smell, seldom foraging at random.

Despite great scientific advances, improved communication is needed to successfully interpret and share bat values with others. Douglas MacFarlane and Ricardo Rocha have taken this into account. By applying conversation psychology, they provide communication guidelines that can help neutralize negative associations between bats and disease. Even scientists with good intentions may inadvertently undermine their message by failing to debunk misinformation.

Falsehoods and fear are easily created through misunderstandings. For example, in Iran and the Mediterranean, myths of mercury-containing “bat nests” began circulating over social media, inciting needless environmental destruction. In response, Iranian researcher, Dr. Hossein Zohoori, teamed up to create Mercury Mirage, a powerful documentary that discredited the untruths with stunning visual evidence.

We congratulate all who are persevering in unveiling the real world of bats in times when investigation, attention and resources have been so severely misdirected toward disease speculation. Discoveries of bat sophistication and values, and effective communication, have never been more important.

An Egyptian fruit bat (Rousettus aegyptiacus) pollinating a baobab flower in Kenya.
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Improving Bat Houses in America:

Nearly 40 Years of Progress and Still Learning

9/14/2020

By Merlin Tuttle

Bat houses are outstanding tools for education. When I introduced them to Americans in 1982, my primary objective was to help people overcome fear and accept bats as valuable neighbors. That goal has been vastly exceeded. Today, hundreds of thousands of American bats live in a wide variety of bat houses.

Individuals who have carefully tested local bat preferences, and adapted accordingly, are reporting close to 90 percent occupancy. Nevertheless, there is still much to be learned. And that is why we’re initiating new collaborations.

Late last month, local member, Debbie Zent, founder of Austin Batworks, reported an impressive event. Her three-chamber nursery house had been caulked, sealed, and painted inside and out, and was mounted high on a streamside ranch building—a nearly perfect combination. But to find it overflowing with occupants just days later was surprising.

This Texas Hill Country bat house became overcrowded within days by Brazilian free-tailed bats (Tadarida brasiliensis).
The house was ideally located approximately 18 feet up on a building beside a permanent creek where it receives only morning to mid-day sun.

Was this extraordinary success due to house or location quality, or were these bats simply desperate?

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Timely New Children’s Book

9/3/2020

By Merlin Tuttle

Life Upside Down

Australia’s Grey-headed flying-foxes

Leading wildlife photographer and conservationist, Doug Gimesy, has teamed up with award-winning media graphic artist, Heather Kiley, to produce an outstanding introduction to the upside-down world of grey-headed flying foxes. Through stunning photography, simple text, and eye-catching design, this book provides a timely introduction to some of the world’s most frequently misunderstood and intensely persecuted animals.

Victims of misunderstanding and mass eradication attempts, Australia’s flying foxes now survive only as tiny fractions of former numbers. Forest clearing has left them homeless and starving. Countless thousands have been killed in mass shooting campaigns, electrocution grids, and flame thrower attacks on their roosts, known as camps. Remnant survivors are now forced to live in cities where they are needlessly demonized as carriers of dreaded diseases, despite a long history of living safely with people or subjected to attempts of forced eviction with nowhere else to go. Welcomed honeybees, dogs, and especially humans are far more dangerous! Moreover, large numbers of flying foxes are essential to reforestation and the survival of much-loved animals such as koalas.

Readers of Life Upside Down will be introduced to the real world of flying foxes as safe and invaluable neighbors and learn how they can be helped. This full-color, large-format, 48-page book is available in hardcover for $19.95 at Australian Geographic or at Book Depository.  

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Bat Flash! Misleading Article Harms Bats and Public Health

7/17/2020

By Merlin Tuttle

A disappointing number of authors and publishers are spreading the false narrative that bats are exceptionally high-risk sources of deadly viruses. The July 12 edition of The Washington Post contained an article titled, “Why do bats have so many viruses?” The author, Rachel Ehrenberg, was apparently unaware of the most recent analysis of viral risks.

We urge Rachel and other Washington Post journalists to review Mollentze and Streiker’s April 28, 2020 comprehensive analysis, published in the Proceedings of the National Academy of Science. Their paper titled, “Viral zoonotic risk is homogeneous among taxonomic orders of mammalian and avian reservoir hosts” concluded that bats are no more likely than other animals to host disease.

Virus hunters have focused search efforts disproportionately on bats, apparently because bats are exceptionally easy to sample in large numbers and have few defenders. Referring to the Covid-19 outbreak, Zhang and Holmes concluded that surveillance of coronaviruses in animals other than bats is critical to protecting against future outbreaks.

Sensational speculation, exaggerating bat association with scary viruses, has led to a serious bias that impedes our understanding of viral pandemics and creates a perfect storm of media publicity. This feeds into our broader academic crisis—the misallocation of large grants for splashy, attention-getting “research” that promotes career advancement over high-quality, reproducible scientific investigation. Such bias threatens to misdirect limited public health resources and halt, or even reverse, decades of conservation progress.

It’s time publishers, authors, researchers, and decision-makers let go of the premise that bats are uniquely dangerous sources of disease and end biased sampling and unsupported speculation. Instead, we need to identify true sources of human infection and insist on accurate reporting that leads to actual prevention.

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Bat Flash! CNN Misses the Mark

Response to CNN Program “Bats—The Mystery Behind COVID-19″

6/16/2020
By Merlin Tuttle

I applaud Anderson Cooper for his attempt to improve public perceptions of bats. His program included numerous reasons why we should appreciate and protect bats. Nevertheless, producers failed to alleviate needless fear by omission of key facts and addition of misleading narratives. Such approaches unfortunately solidify needless fear and can’t be countered by simply sharing bat values. For bats to be tolerated, fear must be eliminated.

Many researchers were reported to “believe” that COVID-19 came from bats. Bats were claimed to be reservoirs for the standard litany of deadliest diseases, including Ebola, though the source of Ebola and COVID-19 remains a mystery. Bats were clearly stated to harbor more zoonotic viruses than other animals, ignoring recent research refuting such claims. Furthermore, scientists shown studying bats wore sealed suits and full-face respirator protection, sending a strong visual message of danger.

A wonderful array of positive things were said about bats, and their essential ecosystem and economic roles were emphasized. However, without putting disease risks in perspective, advising viewers to respect bats while also warning against living near them is high-risk for negative consequences.  

Human encroachment into bat habitats was blamed for pandemic disease threats. However, it was not explained how expanding human populations could reduce pandemic risks simply by ending logging or invasion of new bat habitats. Nor was it explained how bats, restricted to their protected areas apart from where we live and grow crops, could possibly continue to shield us from mosquitoes in our yards or pests that attack our crops. 

Missing elements were conspicuous by their absence. There was no mention of the fact that millions of bats share cities with humans in America, Africa, Asia, and Australia without associated disease outbreaks. Nor was there mention of how easily disease transmission from bats can be avoided—in most of the world by simply not handling or eating bats. Even more troubling is the fact that program producers were well aware of these omitted facts.

On May 7 and 8, production staff conducted nearly two hours of phone interviews with me and Teresa Nichta and received abundant documentation from us. We even offered outstanding video footage showing the popularity of bat-watching tourism in Austin, Texas and planned to schedule filming at various sites in Texas upon their request. They seemed quite excited about our help, promising to get back to us in a few days with final plans. Then, they simply disappeared. We can’t avoid wondering who nixed the production staff’s enthusiasm for sharing such a key demonstration of bats making safe and invaluable neighbors. I suspect that Anderson Cooper will be surprised if ever he learns of this.

The bottom line — Frightened humans seldom tolerate and often kill bats. Programs that promote fear, regardless of good intentions, threaten bats and their essential services as valued neighbors.  

Please remember, there is no credible science documenting that bats are responsible for the transmission of COVID-19, Ebola, SARS, or MERS, to humans. Anyone implying such transmission is speculating. Be vigilant in your media consumption and sharing! 

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Exploring Ecuador’s Los Cedros Reserve

4/15/2020
By Teresa Nichta

This rainy February, we visited Los Cedros Biological Reserve in Ecuador.

Roo Vandegrift, and crew, are filming Marrow of the Mountain; a documentary about the mega-mining now in Ecuador. “In 2017, the amount of land available for mining expanded by hundreds of percent, leaving huge swaths of Ecuador’s most sensitive and biodiverse habitats at the mercy of international mining interests. These concessions appeared suddenly and were sold without public knowledge or consent, especially affecting the mineral-rich and endangered Choco Rainforest.” Roo invited MTBC to conduct a bat survey, which could support litigation to stop the illegal gold mining and help protect the reserve’s unique flora and fauna. The data is to track diversity and endemism at Los Cedros, and analyses are submitted to conservation groups and government agencies, like Critical Ecosystem Partnership Fund and the Ecuadorian state Institute for Biodiversity (part of the Ministry of Environment).

Los Cedros Biological Reserve consists of 17,000 acres of premontane wet tropical forest and cloud forest. Of this, 2,650 acres is formerly colonized land, while the remainder is primary forest. The reserve is a southern buffer zone for the 450,000-acre Cotocachi-Cayapas Ecological Reserve, and both are part of the Choco Phytogeographical Zone. The Choco region is one of the most biologically diverse and endemic habitats on Earth.

Part of its charm is the journey to get there. Monica and I left our Quito AirBnB at 5 am to board a 3-hour long bus ride to Chontal, where we met Marc Dragiewicz of Eyes of the World Films. It was then just a short 30-minute truck ride to the trailhead. 

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