The coronavirus backlash against bats is a bad idea

Fruit bat in flight

In March 2020, hundreds of bats hung crowded in cages in a market in the Indonesian city of Surakata. They waited wide-eyed to be killed and sold as meat. But Covid-19 was spreading, and people in Indonesia and elsewhere were soon blaming bats. The city authorities decided the bats could not be sold and, rather than release them into the wild, they gassed them and threw them into a fire pit, cages and all.

The animals were targeted in what bat biologist Merlin Tuttle has called a “viral witch hunt”. While bats do carry many viruses, there is no evidence yet that they transmitted to people the coronavirus that causes Covid-19. But thanks in part to false stories about the virus originating in bat soup, and to media coverage of a ‘bat-borne virus’, there has been a rise in anti-bat sentiment around the world. This has led to attacks on bats and calls for culls. Now scientists are fighting back. They want us to know that, rather than endangering us, bats bless us in many ways.

Bats eat insects that harm crops or transmit diseases to people and livestock. They pollinate economically and culturally important plants. They disperse the seeds of thousands of plant species, planting the forests of the future. To economies, bats provide services worth billions of dollars. To ecosystems, and so to us all, they are priceless. Yet we are driving hundreds of their species towards extinction, through hunting, habitat loss and heat. The new coronavirus is adding to their threats.

Fear that bats will spread the virus has led people in China to demand that the authorities remove hibernating bats from their houses. It has led people in Singapore to throw live bats down a rubbish chute. It has led people in Egypt to set fires in an abandoned building, killing a hundred fruit-bats with thick smoke. Antipathy towards bats has also increased in Peru and the United States.

“The backlash is very real,” wrote Malaysian bat ecologist and conservationist Sheema Abdul Aziz in March, in an article for Rice. It warned that culls are misguided, ineffective and could potentially make things worse. “I was alarmed by the usual premature speculation and associated scaremongering around bats that always happens after a new disease outbreak,” she told me. “I felt I had to issue a warning before the situation got much worse.”

“Direct transmission of viruses from bats to humans is very rare,” says Sheema, who is president of a Malaysian conservation organisation called Rimba. “We need to explain to people how culling will increase disease risk and accelerate disease transmission, not prevent disease.”

It is true that bats can carry several viruses that have jumped the species barrier to infect people in recent years — including MERS, SARS, Hendra and Nipah. But this does not mean bats are to blame. As Merlin Tuttle pointed out in Issues in Science and Technology in April, the first three of these viruses seem to have been spread to people by animals other than bats, while Nipah is easy to prevent.

The recent emergence of new diseases caused by viruses that originate in wildlife is more to do with human than animal behaviour. Deforestation, hunting and wildlife trade, unsanitary live markets and crowded farms all create the conditions for viruses to ‘spill over’ into human hosts and potentially wreak havoc among us. But regardless of the origins of the Covid-19 virus, it is people, not bats, that are spreading the disease.

“We have been co-existing with bats for centuries and have been largely disease-free,” says Rohit Chakravarty, an Indian PhD candidate at the Leibniz Institute for Zoo and Wildlife Research in Germany, who studies bats in the Himalayas.

“Irrespective of transmission routes, killing bats is never going to be the answer because they are animals that know how to keep their distance,” he says. “It would be more prudent to spend that effort in finding out the exact flow of virus transmission so that proactive mitigation measures can be taken.”

In April, Chakravarty and a fellow doctoral candidate called Baheerathan Murugavel joined a growing chorus of scientists urging people not to stigmatise and persecute bats. They had noticed an increased occurrence of people killing bats and destroying their roosts, in fear of bats spreading the coronavirus. To debunk myths and dispel fears about bats and covid-19, they organised a press statement — signed by 64 bat biologists from across South Asia.

“We should be educating the public to peacefully co-exist with the animals around them instead of getting them culled,” says Murugavel, who is doing research on bats at the Indian Institute of Science Education and Research, in Thiruvananthapuram.

Another scientist warning of a backlash against bats is Huabin Zhao of Wuhan University in China. Writing in the journal Science in March, he warned that: “The exaggeration of bats’ negative traits without regard for their positive ones could ultimately lead to their needless and intentional elimination.”

“Most people do not realize that bats’ populations are decreasing more than ever across the globe,” says Zhao. “We should do our best to convince people that bats are in need of protection more than ever.”

He told me that bats would have a better reputation if more people knew about their positive ecological importance and how research into their unique adaptations can help humanity in fields as diverse as cancer prevention, healthy aging and engineering.

“Communicating how wonderful and amazing bats really are should be a top priority,” says Sheema Abdul Aziz of Rimba. “Ultimately, we need to find ways we can get people to fall in love with bats, and really start caring about bats.”


More reading

Sheema Abdul Aziz: ‘Covid-19: The public scapegoating of bats needs to stop

Merlin Tuttle: ‘A viral witch hunt

Joint statement: 64 South Asian bat biologists bust myths about bats and Covid-19

Huabin Zhao: ‘COVID-19 drives new threat to bats in China

Rimba: ‘FAQ on bats and Covid-19’ (also available in Bahasa Malaysia and simplified Chinese)

Bat Conservation International: ‘ FAQ on bats, coronaviruses and zoonotic disease

Photo credit

Andrew Beresford / Flickr (Creative Commons)

Frying eggs, flying foxes, dying wasps, crying shame

Crack an egg in a pan, turn up the heat and you can witness a kind of magic. In just seconds the viscous egg solidifies. And despite the rising heat, it’s the opposite of melting that occurs. I was a teenager when I heard a biology teacher explain this paradox: “The egg is full of proteins and the heat has denatured them”. Denatured. The word was new to me. Twenty-five years later I find it is a fitting descriptor of more than just wayward proteins.

My teacher had explained that every protein has a temperature at which it will function best. Too hot or too cold and the protein’s shape can buckle or break. It will no longer be able to bond with other chemicals. It will cease to work. I think about that fried egg often when I consider what rising temperatures could mean for the planet.

We know that when people die of heat stroke, part of the problem is that some of their proteins have denatured. Could our cells become our jailors?

The proteins inside us and every other living thing vary greatly. Some tolerate heat better than others. Others begin to destabilise at just a couple of degrees warmer than normal. It is not the average protein that poses a problem, but the weaker links, those most liable to destabilise in extreme heat. We don’t know yet which of them are also critically important – to our food crops for instance.

As the world warms, what will happen to the millions of different proteins in the millions of different species, from spores to sperm whales, soil bacteria to sunflowers? These invisible structures are central to life itself. They give shape not only to hair and to horn but also to hormones and enzymes and DNA. They are the messengers and mechanics that control and correct processes in and between cells. Like the gaps in music that make the beats thrilling, these in-between places are where wonder is born.

It’s the same between species. Life is not a zoo of caged individuals living in isolation but a web of shared destiny. And while activists go on about polar bears or other creatures in danger, I am more curious about what climate change could mean for the way species interact and provide us gifts as a result. It’s been on my mind since the early years of my career when I lived in a rainforest in Borneo and studied the most fascinating of plants, the strangler figs.

Every one of the 750 or more species of fig trees depends for survival on its own species of tiny wasps to pollinate its flowers. The wasps in turn depend on the figs, the only places in which they can lay their eggs. This mutual reliance combines with the wasps’ short lifespans to ensure figs are available year-round, and because of this they sustain more species of birds and mammals than other plants. In return for the fig flesh those creatures disperse the trees’ seeds, and provide the same service to thousands of other rainforest plants. These interactions between fig trees and animals help to sustain the great rainforests of the world.

What does this have to do with climate change? Researchers have shown that just a small increase above current temperature levels will shorten a fig wasp’s life to just a couple of hours – not enough time to find a fig, pollinate its flowers and lay eggs. No pollination would mean no ripe figs for animals to eat, and this would mean fewer seeds get spread from place to place. Tree species that form a key part of the forest and its capability as an ensemble to lock away carbon are likely to suffer.

The tiny wasps are frail but some of the fig trees’ bigger partners are at risk too. They include fruit bats called flying foxes that can carry seeds 50 kilometres or more before pooping them out, making them some of the most effective seed dispersers around. Their vulnerability became clear early in 2014 when thousands of them fell dead from the sky during a blistering heat wave in Queensland, Australia. For both the bats and the fig wasps, the heat was too much. It will have interfered, at a cellular level, with proteins that cooked and then closed for business. These snapshots suggest trouble in store for the fig trees and the forests, whose fates entwine with our own.

Ecology teaches us that no species is an island. It’s a lesson our leaders seem to have skipped. It shows us we’re all in this together, the fig wasp and the fruit bat, the you and the me. That’s what makes the human fingerprints all over climate change all the more ironic. As we develop societies ever more distant from nature to protect ourselves from its wild whims, we risk unleashing upon these denatured societies powers we cannot hope to control or even predict.

This post reproduces my contribution to Culture and Climate Change: Narratives, which launched on 24 June at the Free Word Centre. The whole book is available for free and anyone can reproduces its articles under a Creative Commons Licence.