bat research Archives - Merlin Tuttle's Bat Conservation

Saving Bats One Cave and Mine at a Time

April 23, 2021July 8, 2021 Conservation

4/23/21
Merlin Tuttle

Caves are a critical resource for America’s bats. But thousands are no longer available for bats. Early American settlers relied on saltpeter from bat caves to produce gun powder. Then caves became lucrative for tourism, and many others were buried beneath cities or flooded by reservoirs. Even caves that were not destroyed often were rendered unsuitable for further bat use. Not surprisingly, the most cave-dependent bats quickly crashed to endangered status.

Today, nothing is more important to their recovery than identifying, restoring, and protecting key caves of past use. At that, Jim Kennedy is an unsung hero. Early in his career he joined me in critical research on the needs of cave-dwelling bats and worked with master bat-gate-building engineer, Roy Powers, to become an expert builder.

Kennedy became an expert at detecting evidence of past use by bats, and he has helped build gates to protect many of America’s most important remaining bat caves. He has also led workshops to train others. In 2013, he founded his own company, Kennedy Above/Under Ground, LLC. His teams have built 56 protective gates at 43 caves and abandoned mines where hundreds of thousands of bats have since recovered from severe losses.

Illustrative of the impact of protection at key locations, endangered gray bats at Bellamy Cave in Tennessee, increased from 65 to more than 150,000 once protected. And when a bad gate was replaced at Long Cave in Kentucky, gray bat numbers grew from zero to over 300,000. At Saltpeter Cave in Kentucky, endangered Indiana bats increased from zero to 7,000 when poor gates were replaced, air flow was restored, and winter visitor tours were terminated. Jim was involved in restoring each of these caves for use by bats.

Protection can be a real challenge. Even good gates, if wrongly located, can force abandonment partly because different species have unique needs. Gray bats, and other species that form large nursery colonies in caves, cannot tolerate full gates across entrances. Newly flying young slow down and become easy prey for predators. Jim has three ways of dealing with this. When a cave entrance is large enough, he leaves fly-over space above, relying on a perforated metal lip to prevent human entry. Alternatively, he sometimes builds a metal chute at the top, using perforated metal. When entrance size or shape precludes such approaches, he surrounds the entrance with a 10-foot-tall, perforated-steel fence. At Key Cave in Alabama, the Tennessee Valley Authority contracted Jim’s team early in 2021 to build a 390-foot fence that required 21 tons of steel. Its entrances were too small to permit young bats safe exit through gates.

Comments on World Health Organization’s COVID-19 Report

April 5, 2021April 13, 2021 Disease

The World Health Organization’s recent report on COVID-19 speculates a bat origin. However, its findings are seriously flawed and questioned by the Biden administration according to the Wall Street Journal. Former CDC Director, Robert Redfield, in his CNN interview, still believes it escaped from a lab in China. The origin clearly remains unresolved.

A review of scientific literature reveals that SARS-CoV-2, the coronavirus that causes COVID-19, has not been found in bats, and there are no reports of transmission from a bat to a human.

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

January 28, 2021February 19, 2021 Bat Flash

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.

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.

Contact USA Today
- Email authors Elizabeth Weise and Karen Weintraub at eweise@usatoday.com; kweintraub@usatoday.com
- Email the President/News and Publisher, Maribel Perez Wadsworth, at maribel@gannett.com
- Email Corrections at accuracy@usatoday.com
- Call USA Today at 703-854-6000 or 1-800-872-7073
- Twitter @USATODAY
- Facebook @usatoday
- For additional contact info, click HERE

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

November 3, 2020November 9, 2020 Bat Flash, Disease

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. A 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.

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

October 15, 2020November 9, 2020 Bat Flash

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.

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.

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.

Bat Flash! Misleading Article Harms Bats and Public Health

July 17, 2020September 21, 2020 Bat Flash

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.

49th NASBR in Kalamazoo, Michigan

November 7, 2019February 14, 2020 Conservation

The 49th Annual North American Symposium on Bat Research was held in Kalamazoo, Michigan on October 23-26, 2019. It was hosted by Amy Russell and Maarten Vonhofm amidst a quintessential Midwestern autumn. There’s no better place to keep up with the latest bat research technologies and discoveries or for graduate students to explore career options. Many of the researchers attend every year, developing lasting friendships and invaluable networking opportunities. Not surprisingly, this is Merlin’s favorite group. He hasn’t missed a meeting in 49 years. This year, Merlin joined Brock and Sherri Fenton and Price Sewell in presenting an enthusiastically received pre-conference workshop on bat photography.

Our hospitable hosts, Amy Russell and Maarten Vonhofm.

Merlin especially enjoys opportunities to encourage students in conservation-related careers and takes great pride in the achievements of those he has helped. Four joined Merlin for the organization’s annual “Lunch with a Mentor” program to discuss career path choices, conservation interests, and of course, to hear a few of Merlin’s wild adventure stories. They also got a perspective from Teresa who sat in on the meeting. (Check out Advice for Young People Interested in Science and Conservation) (more…)

A Model Example of Bat Recovery Potential

September 25, 2019July 27, 2021 Conservation, Field Work/Photography

By Merlin Tuttle
9/25/19

Long Cave, in Kentucky, like many others, has a long history of human occupation with little record of prior use by bats. It was mined for saltpeter, a key ingredient of gun powder, during the war of 1812 and was subject to commercial tourism, probably beginning at about the turn of the century, ending by the 1930s.

Huge passages trapped cold air and remained cool year-round, offering major opportunities for bat hibernation. Roost stains from past bat use were widespread, and the cave clearly had potential to shelter millions. As recently as 1947 some 50,000 bats, presumed to be largely the now endangered Indiana myotis (Myotis sodalis), continued to return in winter. Nevertheless, entrance barriers built to exclude non-paying tourists, increasingly restricted air flow, eventually culminating in a concrete wall and a nearly solid door.

The bat population plummeted, leaving only roost stains as evidence of extraordinary past use. By the time that Mammoth Cave National Park was established in 1941, few bats could be found in the park’s caves, and those that remained weren’t yet recognized as either important or endangered.

By the early 1990s, as characteristic bat roost stains began to be recognized, the huge historic importance of several of the park’s caves began to be suspected. Cave Resource Management Specialist and Research Coordinator, Rick Olson, invited me and several colleagues to lead an investigation. We quickly found unmistakable evidence, of past use by at least 9-13 million bats, perhaps more than twice that many, mostly endangered gray (Myotis grisescens) and Indiana myotis.

Experiencing Texas Bats

April 24, 2019July 12, 2019 Field Work/Photography, Members

By Renee Anna Cornue
4/22/19

As MTBC’s Photo Collection Administrator, much of my responsibility lies behind a computer screen. I’d seen thousands (about 120,000 if we’re being real) of photographs from Merlin’s most-active field work days, preparing me for what to expect as much as photographs can. I’d seen mist nets, harp traps, banded bats, guano piles, and evidence of the bats’ incredible diversity.

Though fortunate to see Austin’s bats in a variety of ways, I’d never worked with bats first-hand. On this trip, I was most excited to step away from the desk and learn how bats are studied in the field, especially surrounded by knowledgeable and talented peers.

As with MTBC’s past adventures, our trip was a hands-on working trip with invaluable time and expertise contributed by leading colleagues from varied specialties. We were in the company of expert bat researchers, photographers, videographers, rehabilitators, consultants and passionate citizen scientists as we searched for some of the least known bats in the U.S.

(more…)

Counting Free-tailed Bats in Bridges

September 18, 2018January 22, 2019 Bats, Conservation

9/10/18
By Merlin Tuttle

Merlin inspects Brazilian free-tailed bats (*Tadarida brasiliensis*) moments after removing them from their bridge crevice roost for counting.

For many years we’ve wondered just how many Brazilian free-tailed bats (Tadarida brasiliensis) could cram into a single 18-inch-deep bridge crevice. Accurate counts of large colonies are difficult no matter how they’re made. However, when estimating bridge colonies, it would help if we knew the number, using an average horizontal foot of crevice.

The solution seemed easy. Two years ago, Glen Novinger, an MTBC member and I, inserted two, three-quarter-inch-thick wooden frames, each encompassing a square foot of interior space, into bridge crevices of the same width while the bats were out feeding. The idea was to later slowly remove them, forcing those roosting inside to exit into a cloth-lined bag from which we would count them.

However, the bats were full of surprises. The first night we waited patiently till half an hour after we’d seen the last ones leave—or at least that was what we thought! But when we approached to install our devices, roughly half remained inside. I couldn’t help but wonder how many emergence counts had missed those that, for whatever their reasons, didn’t emerge at sundown. (more…)