Amidst the coronavirus pandemic, why bats need our backup – not our blame.

Already maligned and misunderstood, the coronavirus crisis has done little to improve attitudes towards bats. Yet as these experts reveal, they’re vital for the health of the planet – and us.

Tuesday, June 9, 2020,
By Lauren Jarvis
A Mediterranean horseshoe bat (Rhinolophus euryale). This family of bat species take their name from the ...

A Mediterranean horseshoe bat (Rhinolophus euryale). This family of bat species take their name from the distinctive shape of their nose leaf. Subspecies are spread throughout the world; this one was photographed in the Caucasus. Horseshoe bats have been named as a potential reservoir of the virus that causes COVID-19. 

Photograph by Ivan Kuzmin / Alamy

“WHOEVER said one person can’t change the world never ate an undercooked bat.” This is just one of many memes shared around the globe since SARS-CoV-2– the coronavirus causing COVID-19 – jumped species, infected humans, and triggered one of the deadliest pandemics in modern history. 

Not just the butt of poor-taste jokes, bats have found themselves in the firing line both metaphorically and physically since a species of horseshoe bat was identified as the likely reservoir for the virus that stopped the world. With their numbers already in decline due to deforestation, hunting and climate change, culling by misguided governments and panicked communities in countries including Indonesia and Peru is the last thing these misunderstood and much-maligned mammals need. 

“Bats are an easy target,” says Kate Jones, Professor of Ecology and Biodiversity in the Centre for Biodiversity and Environmental Research at University College London. “According to common myths, they’re sinister, they suck blood, they're weird and they get in your hair. They’re very easy to blame for our current predicament.” 

Mexican free-tailed bats emerge from a cave in Carlsbad Caverns National Park, New Mexico, at nightfall. Bat colonies sometimes comprise numbers of individuals in the millions; this species holds the record for the largest colony, at some 20 million bats. Predictably, this makes them particularly incompatible with any kind of social distancing.

Photograph by Walter Meayers Edwards/National Geographic Creative

But Professor Jones is smitten, not spooked. This is despite the role bats have played in the current global crisis and her own personal health emergency, triggered after conducting field studies on a colony deep in the jungles of Latin America. 

A bat fan for over 30 years, Jones has studied their ecology, evolution and conservation, held the chair of the UK’s Bat Conservation Trust, and now works on bat research projects around the globe. It was on an early scientific expedition that they first made an impact. 

“I was in my twenties, researching the effects of hurricanes on biodiversity, when I caught the bat bug – in terms of fascination and a disease,” explains Jones. The infection was histoplasmosis, caused by breathing in spores of the fungus, Histoplasma capsulatum, found in bat and bird droppings. 

While Jones recovered quickly at the time, later bouts of pneumonia revealed her lungs were covered with calcified nodules as a result of the infection. In today’s locked-down world, she’s considered high risk.  

Details of bat faces illustrated by Ernst Haeckel in 1904's Kunstformen der Natur hint at the fascination with the varied and expressive physiology of the only flying mammals – and their potential to be hijacked for sinister applications, famously by Bram Stoker with 1897's Dracula. The illustration shows (1-2) Brown long-eared bat (3) lesser long-eared bat (4) lesser false vampire bat (5) big-eared woolly bat (6-7) Tomes's sword-nosed Bat (8) Mexican funnel-eared bat (9) Antillean ghost-faced bat (10) flower-faced bat (11) greater spear-nosed bat (12) thumbless bat (13) greater horseshoe bat (14) wrinkle-faced bat (15) spectral bat.

Photograph by Ernst Haeckel / Image and legend information via Wikimedia Commons

“In retrospect, wading around in guano deep inside one of Puerto Rico’s largest caves, surrounded by four million bats and without any kind of P.P.E. wasn’t the best idea,” Jones admits. “Bats changed my world then, and now they’ve changed it for everyone – but in both instances it’s humans, not bats, we should blame.”

Pandemic prime suspect

As scientists, conspiracy theorists and Presidents continue to investigate, spin and speculate on the original source of COVID-19, the leading contender remains Rhinolophus affinisa species of horseshoe bat. Coronavirus samples collected from a colony in southwest China in 2012 showed a 96% genetic match to SARS-CoV-2. Whether the virus jumped directly from bat to human, or travelled via an intermediate host such as the oft-cited pangolin, is still an open question. 

“Current evidence doesn’t point to bat-pangolin-human transference. It could have gone directly from bats to people, or another wild or domestic host could be involved,” explains Dr. Kevin Olival, Vice-President for Research at EcoHealth Alliance, an organisation that has been investigating emerging infectious diseases for over 20 years. 

“Horseshoe bat species known to carry SARS-related coronaviruses range widely throughout Southeast Asia, so a lot of scenarios could be applied here. The virus could even have emerged in a different country and travelled through people to China. Surveillance for coronaviruses in their natural hosts has been patchy in many countries, and may be why we haven’t found an even closer match to SARS-CoV-2. As yet, we don’t have a complete picture,” says Olival.

Bats for sale as food at a traditional market in Asia. Such markets – where densely-caged live animals, including those taken from the wild, are butchered on-site and sold for human consumption – have been identified as opportunities for zoonotic viruses to jump species. The Huanan Seafood Wholesale Market in Wuhan has been widely publicised as the potential source of the COVID-19 pandemic.

Photograph by Maurizio Biso / Alamy

Some of the facts we do know, thanks to research by organisations like the EcoHealth Alliance and according to the World Health Organisation (WHO), is that 61% of all human diseases are ‘zoonotic’ – passed from animals to humans – as are 75% of all new diseases discovered in the last decade. While animals can live quite happily with their own pathogens, once transferred through the air, food consumption, contact with other animals or directly from bites to humans, viruses can rapidly spread, mutate and wreak havoc with human populations – and global economies. 

In addition to their link with COVID-19, which at the time of writing has infected just under 7 million people across the globe, bats have also been identified as likely reservoirs for the viruses that cause SARS (Severe Acute Respiratory Syndrome)MERS (Middle East Respiratory Syndrome) and EVD (Ebola Virus Disease), with other animals understood to be intermediate hosts. Infected during ‘spillover’ events, the virus often mutates inside the new host species, increasing its virulence, before spilling over again into humans. With SARS, the intermediate was the civet cat; in MERS, it was dromedary camels, while chimpanzees and gorillas have contracted EVD. Domestic animals can also play host, with pigs and chickens linked to the devastating influenza pandemics H1N1(Swine Flu) and A1 (Avian Influenza), while HIV (Human Immunodeficiency Virus) originated in primates, and vector-borne viruses including Zika, dengue and yellow fever were originally transmitted from primates to humans by mosquitoes.

“As a scientist, the more you look for viruses, the more you find,” says Professor Jones. “There are over 1,400 species of bats, so we’d expect them to have lots of pathogens, but they don’t carry significantly more viruses than other animals like rodents, birds or carnivores.” However, where bats may lead the field is metabolically. 

(Related: Why do only some viruses infect us?

Professor Kate Jones in the field. During an earlier field trip she contracted histoplasmosis, but she remains an staunch advocate. “Bats changed my world then, and now they’ve changed it for everyone,” she says, “but in both instances it’s humans, not bats, we should blame.” 

Photograph by Kate jones

“Bats are very long lived for their body size – something that can teach us not only about disease, but also ageing.” Kevin Olival of EcoHealth Alliance releasing a bat after study. 

Photograph by EcoHealth Alliance

Natural technology in action

“Bats are the only flying mammal, and they radically ramp up their metabolism every night to be able to fly around and hunt for food, which can cause a lot of inflammation and cellular damage” explains Dr. Olival. “Somehow they’ve adapted to cope with that inflammation and repair their DNA. As a result, there’s a lot of exciting research looking at bat immune function to understand new potential treatments and human longevity. Bats are very long lived for their body size – something that can teach us not only about disease, but also ageing.”

Their repair mechanisms could also be protecting the mammals from viruses related to SARS-CoV-2 which cause extreme damage in other hosts, including humans. “Bats fly at high body temperatures,” says Jones, “whereas human body temperatures can’t safely run high enough to kill a virus. These amazing metabolic adaptations could help us to understand how we deal with a range of diseases in the future.” 

Of the many lessons to be learned from COVID-19, one of the most important must be that zoonosis research is humankind’s strongest weapon of self-defence. Previous studies of zoonotic diseases facilitated the early identification of the novel coronavirus SARS-CoV-2, and fast-tracked awareness of its potential to trigger a deadly pandemic. Research will also play a vital role in predicting and preventing future cataclysmic outbreaks, and be key in the race to find effective vaccines. 

(Learn why British zoos are starving to death in light of the coronavirus pandemic.)

Ebola graves from the 2014 outbreak in Kenema, Sierra Leone. Ebola zaire is a virus also thought to find a natural host in bats – in this case likely fruit bats of the family Pteropodidae. Human encroachment into the bats' forested habitat and consumption of bushmeat likely led to the virus's jump to human.

Photograph by Tommy E Trenchard / Alamy

Yet shortly after President Trump first threatened to halt U.S. funding to WHO in mid-April, the National Institute of Health – the U.S. agency responsible for public health and biomedical research – terminated its $3.4 million (£2.7 million) grant to EcoHealth Alliance after an 18-year relationship. The Alliance’s collaborative research into bat-borne viruses with international scientific institutions including the Wuhan Institute of Virology – the Chinese biosecure research facility at the centre of the unproven COVID-19 virus-leak theory – now hangs in the balance. 

“For 20 years, we’ve been partnering with some of the most respected scientific institutions around the world, trying to discover where coronaviruses come from, identifying the global ‘hot spots’ where new viruses could potentially emerge, and understanding the underlying drivers that lead to them spilling over to other animals or humans,” says Olival. “It’s important work, and I hope more funding will become available to drive it forward in the future. It’s essential if we’re to fully understand the grave risks these viruses present to humanity.” 

For now, while virologists are working in laboratories around the clock to develop a vaccine against COVID-19, scientific bat research in the field is on hold: not because researchers are at risk of viral infections from bats, but to prevent scientists accidentally transferring the novel coronavirus into new colonies. (Here's why a coronavirus vaccine could take way longer than a year.)

Dr. Winifred Frick conducting fieldwork on bats in Jamaica as part of conservation efforts to protect the habitats of the endangered Jamaican flower bat and Jamaican funnel-eared bat. 

Photograph by Winifred Frick

“The tendency is to scapegoat wildlife, but the culpability here is in the way we treat the planet.”

Dr Winifred Frick

“Pathogen transfer can flow both ways,” explains Dr. Winifred Frick, Chief Scientist at Bat Conservation International and a National Geographic Explorer. “So right now, we need to be sure we don’t introduce the SARS-CoV-2 virus into naive bat species.”  

Frick has good cause for concern, having witnessed first-hand the devastating impact an invasive soil fungus, Pseudogymnoascus destructans, has had on North American bat populations, after being accidentally introduced to a cave where bats hibernate in up-state New York. 

Believed to have walked in on the boots of visiting European cavers, the fungus causes white-nose syndrome (WNS), an emergent disease which infects the skin on the muzzle, ears and wings of hibernating bats. Prematurely woken by the irritation, they burn through their fat stores and die. With bats particularly bad at social distancing, the disease has now spread across 33 states in the USA and seven Canadian provinces, killing over 6.5 million bats since first being identified in 2006, and leaving some species in danger of extinction.

(There's a bat apocalypse unfolding. Can scientists stop it?)

Protecting the bats

“When I first started working with bats, we didn’t give P.P.E. a thought,” says Frick. “We were vaccinated for rabies and wore gloves, mainly to stop being bitten. But after white-nose syndrome arrived in the USA, things had to change.”

Bat people work in extreme environments. Tropical underground cave systems can see temperatures reach the high thirties, while high humidity and acrid guano – with its potential to harbour histoplasmosis – test even the most dedicated of teams. “Masks or respirators are now widely used,” says Frick, “and boots and equipment are decontaminated after any field work. It’s essential for protecting both ourselves – and the bats.”

Given the current pandemic, the thought of bats requiring our protection may seem paradoxical, but it’s needed now more than ever. While they constitute a quarter of all mammalian biodiversity, a third of all species are considered to be under threat, with 77 Endangered and Critically Endangered bats on the IUCN Red List. And as the crisis deepens, it’s becoming clearer by the day that had we been better neighbours to bats and other animals, and responsible guardians of their habitats, the COVID-19 tragedy may never have happened at all.

Mediterranean Horseshoe Bat (Rhinolophus Euryale) in flight, North Bulgaria. Bats are so associated with this area of Eastern Europe they featured on a series of commemorative postage stamps in 1989. 

Photograph by imageBROKER / Alamy

“Bat research in the field is on hold: not because researchers are at risk, but to prevent scientists accidentally transferring the novel coronavirus into new colonies. ”

“The tendency is to scapegoat wildlife, but the culpability here is in the way we treat the planet,” says Dr. Frick. “There is a growing body of evidence to suggest that habitat destruction, increased human-wildlife conflict, bushmeat hunting, poaching and trafficking are the drivers of increased zoonotic disease risk.” The clearing of vast areas of forests in developing nations is bringing humans ever-closer to wildlife, exposing people to hundreds of unknown pathogens – each one harbouring the potential to spark the next pandemic. “We tend to want a simple narrative and someone or something to blame, even if it’s a wild animal like a bat,” says Frick. “But these are extremely complex problems with highly complex solutions.”

Perhaps the pause button that’s been pressed by the pandemic has yielded an unprecedented opportunity to rethink the world – and demand more from our leaders than ‘business as usual’. That, it would seem, may be exactly what brought us here.   

“Conservation is a critical part of the solution for global health and human safety,” says Frick. “Breaking our relationship with nature, through destroying habitats and rampant wildlife exploitation, increases the risk of pathogens being transferred from animals to people. When we protect bats, other wild animals and their habitats, we’re helping to keep nature’s balance. That’s not just good for the planet, it keeps all of us safer and healthier, too.” (Want to prevent pandemics? Stop disrespecting nature, says this leading scholar.)

Bats’ right to live free and undisturbed in healthy ecosystems is increasingly a challenge. When they’re not being driven to find new roosts due to deforestation, trapped and transported to be sold alongside dismembered wildlife in markets, or forced to feed in farmers’ orchards when native trees are felled for timber or to plant oil palms, they go gently about their nocturnal business. Using complex echolocation to navigate, they pollinate more than 500 species of plants – including cash crops like mango, banana and agave – disperse seeds, and devour millions of insects that would otherwise spread disease and decimate harvests.

“Bats are critical species, providing a huge range of ecosystem services for us and our planet,” says Professor Jones. “But they’re also just endlessly fascinating and cool: what’s not to love?” 

Follow Lauren Jarvis on Instagram.

 

In pictures: The varied, fascinating bat 

Read More