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)

How poop could counter calls to resume commercial whaling

This post was first published by Scientific American in August. As such, it refers in the future tense to a meeting that took place back in September. You will find an update — and some good news — at the end of the story.

Before whales dive into the darkness of the deep ocean they often come to the surface and release a huge plume of faecal matter—which can be the colour of over-steeped green tea or a bright orange sunset. When Joe Roman, a conservation biologist at the University of Vermont, saw one of these spectacular dumps in the mid-1990s, he got to wondering: “Is it ecologically important? Or is it a fart in a hurricane?” Continue reading

Kill off the animals and you change the forest — fast

Last year I brought you the story of Lambir Hills National Park, a Bornean forest in which I used to live and work, where hunting and other pressures have forced into extinction much of the biggest wildlife species (see The near empty forest that proves conservation is failing).

It describes how recent surveys had failed to find 20 percent of the park’s resident bird species and 22 percent of its mammal species. The forest is emptying fast. The losses include half of the park’s primate species and six out of seven hornbill species —  all important dispersers of rainforest seeds. Sun bears and gibbons, bearded pigs and flying foxes all once called Lambir Hills home. Today it is hard to find an animal that weighs more than a kilogram in the national park.

Now researchers have shown what these extinctions mean for the forest itself. Rhett Harrison and colleagues tracked the fates of over 470,000 trees of more than 1,100 species for a 15-year period since intense hunting began there.

In a new study published in Ecology Letters, they have shown that the forest has changed markedly. There are far more trees now — the density of saplings increased by over 25 per cent between 1992 and 2008 — probably because there are fewer deer and other mammals to eat the young plants. But overall the diversity of trees has fallen. And compared to species that rely on gravity or wind to spread their seeds, there has been a relative decline in the number of new trees from species that depend on animals to disperse their seeds.

Species with animal-dispersed seeds — especially those with bigger seeds — are also more clustered than they were before hunting took off. This is probably because the loss of large fruit-eating animals means that seeds, on average, now travel shorter distances. There was no increase in clustering among species that need no animal assistance to spread their seeds.

The authors write: “Fruit that would formerly have been eaten by hornbills, gibbons or fruit pigeons, all of which are efficient long-distance seed dispersers, are now unlikely to be fed on by anything larger than a bulbul or a barbet”. For those of you who don’t know the birds of Borneo, members of the latter two types are both small enough to fit in a trouser pocket.

The researchers could draw their conclusions because Lambir is home to one of the world’s longest running forest studies. In 1992, scientists marked out a 52 hectare patch of the forest and then tagged, measured, mapped and identified every tree bigger than 1 cm diameter at breast height. In 1997, 2003 and 2008 they went back and repeated the exercise, each time taking several months to complete the task.

Their massive datasets, which track the identity and positions of around half a million trees every 5-6 years can animate the forest’s history. Like the photographs that form time-lapse videos, these periodic census snapshots reveal the patterns of life over time.  The next census of the 52-hectare plot, which is due to take place soon, will add a critical fifth image that further refines the picture of a forest in flux.

The results are already striking but, as the authors note: “the full impacts of defaunation at Lambir are only likely to be realised over several plant generations.” So far, none of the species that depends on big animals to disperse its seeds has gone extinct. That’s just a matter of time.


Harrison, R. D. et al. 2013. Consequences of defaunation for a tropical tree community. Ecology Letters. Article first published online: 12 MAR 2013 DOI: 10.1111/ele.12102

The near empty forest that proves conservation is failing

Boleh makan… Boleh… Boleh.” As I turned the pages of my copy of Mammals of Borneo to reveal more images of wildlife, Siba anak Aji said the same thing each time. “Can eat… Can… Can.”

It was 1998 and I was doing ecological research in Lambir Hills National Park in Sarawak, Malaysian Borneo. Siba, my research assistant, was explaining which of the wild species his Iban community would consider eating. The list was long.

The only animal off the menu was the moonrat. Little wonder — this weird white creature, which is not a rat but a cousin of the hedgehog, stinks of ammonia. Everything else, said Siba, was fair game.

Hunting was of course banned in Lambir Hills and for Siba and many other members of his community the park was a source of jobs not meat.

But for others the forest was a larder. Continue reading