Why we shouldn't be so quick to demonise bats

December 22, 2017 by Justin Welbergen And Kyle Armstrong, The Conversation
Credit: Justin A. Welbergen, CC BY-NC-SA

Australian health authorities regularly issue public reminders not to touch bats because they can host Australian Bat Lyssavirus (ABLV). This type of health education is necessary because it reduces human exposure to bat-borne diseases. However, subsequent sensationalist media reporting risks demonising bats, which increases human-wildlife conflict and poses barriers to conservation.

Bats are remarkable native creatures of key ecological and economic importance. We urgently need more matter-of-fact style reporting around the risks of bat-borne diseases to avoid vilification and persecution of these unappreciated mammals.

Australia's weird and wonderful bats

Australia has 81 bat species, from nine families. They comprise the second-largest group of mammals after marsupials (159 species). They range in size from the little-known northern pipistrelle that weighs less than three grams and ranks amongst the smallest in the world, to the black flying-fox that can weigh more than a kilogram and is among the world's largest.

Bats play many different roles in Australian ecosystems. The southern myotis or "fishing bat", for example, has long toes that it uses to rake up small fish and invertebrates from rivers, lakes and ponds. The golden-tipped bat delicately plucks spiders from their webs, while the ghost bat feeds on large insects, rodents, birds, and even other bats. These are examples of "microbats"—species that use echolocation to find their way in darkness and detect prey.

Face of an eastern tube-nosed fruit bat (or ‘Shrek bat’), a solitary bat with long tubular nostrils that are thought to prevent fruit juices from running up its nose. Credit: Justin Welbergen

Australia is also home to nine "megabats"—species that rely on large eyes and a keen sense of smell to find pollen, nectar, or fruit. The common blossom bat, for example, is a mouse-sized fruit bat with a very long tongue for feeding on nectar; the eastern tube-nosed fruit bat is a solitary bat with long tubular nostrils that are thought to prevent fruit juices from running up its nose; and the little red flying fox is adapted for long-distance flight, travelling thousands of kilometres across the Australian landscape in search of food.

Bats are largely nocturnal and inconspicuous, except for those flying-foxes that sometimes appear in large numbers in urban environments where they can be cause for much frustration and conflict.

All bats are vulnerable to a range of human threats, including the clearing of foraging areas and the loss or disturbance of roosts. Thirteen of Australia's are now listed as "threatened" under our national conservation legislation. Australia's most recent extinction was a bat: the Christmas Island pipistrelle winked out of existence forever in 2009 following a sluggish federal government response to calls for urgent conservation action.

Why are bats important?

Bats are important in two ways. First, each species has its own value as a part of Australia's natural and cultural heritage. They are fragile creatures, but tough enough to survive and thrive in the harsh Australian bush—if they are given the chance.

A selection of Australia’s bat diversity (Top row from left: grey-headed flying-fox; orange leaf-nosed bat; common blossom bat; southern myotis; Bottom row: golden-tipped bat; eastern horseshoe bat; common sheath-tailed bat; ghost bat). Credit: Justin Welbergen (grey-headed flying-fox, eastern horseshoe bat); Nicola Hanrahan (ghost bat); Bruce Thomson (golden-tipped bat); Steve Parish & Les Hall for remainder of species

Second, microbats provide valuable ecosystem services because many are voracious predators of insects, including many agricultural and forestry pests. Megabats, meanwhile, provide long-distance pollination and seed-dispersal services, helping to maintain the integrity of Australia's increasingly fragmented natural ecosystems.

Australian bat lyssavirus

Some Australian bats are hosts for Australian bat lyssavirus (ABLV) that can cause a rabies-like disease in humans and potentially pets. Since its discovery in 1996, there have been three human deaths from ABLV in Australia.

The virus is rare, and its prevalence among bats is thought to be less than 1%. But it is more common among sick, orphaned, or injured bats – that are in turn more likely to end up in hands of the public.

A rabies vaccine has been around since the time of Louis Pasteur, and when combined with proper wound management and prompt medical care, is very effective in preventing the disease. Rabies vaccine that is given after exposure to ABLV, but before a person becomes unwell, can still prevent the disease. But once a person develops the disease there is no effective treatment.

Bats such as the grey-headed flying-fox (left) and the Christmas Island flying-fox (right) provide expensive pollination services for free. Credit: Justin Welbergen (left); Carol de Jong (right)
"No touch, no risk"

As long as we do not touch bats we are not at risk. Yet despite this simple message, many people still handle sick or injured bats, even though this is the major cause of potential exposures to ABLV.

Humans are not exposed to ABLV when bats fly overhead or feed or roost in gardens. Bat urine and faeces are not considered to be infectious, and tank or surface water contaminated with these substances is also not a threat.

The primary ABLV transmission route is through bites or scratches, bringing infected bat saliva into direct contact with the eyes, nose or mouth, or with an open wound. Therefore, the best protection by far is to avoid handling bats.

If you do get scratched or bitten by a bat, the Australian Department of Health recommends that you immediately wash the wound thoroughly with soap and water for at least five minutes, apply an antiseptic with antiviral action, and seek medical attention.

Image of Australian bat lyssavirus. The finger-like projections are the virus, as it is shown budding off from a cell. Credit: Electron Microscopy Unit, Australian Animal Health Laboratory, CSIRO

Prevention is better than cure, so people should never handle bats (or other wildlife) unless they are trained, vaccinated, and wearing appropriate protective gear. If you find an injured or sick bat, the best thing to do is to contact your local wildlife agency or veterinarian.

Reporting without the demonisation

Bats already have a dark reputation in folklore, myths, and modern culture. This is exacerbated by negative media attention following public health warnings and health research.

We strongly encourage a more matter-of-fact style of reporting around the risks from bat-borne diseases. You are much more likely to be killed by lightning or by falling out of bed than by a bat.

Granted, the risks posed by bat-borne diseases are relatively new to most of the public, but more nuanced framing can effectively support both public health and wildlife conservation goals. So while you remember to slip-slop-slap, be croc-wise and snake aware, and wear gloves when gardening, you should also add "don't touch bats" to your common-sense repertoire.

Explore further: Wind farms along mountain ridges may negatively affect bats

Related Stories

Wind farms along mountain ridges may negatively affect bats

November 1, 2017

By attaching miniaturized Global Positioning System tags to cave bats near a mountain ridge in Thailand, researchers have shown that bats repeatedly use mountain slopes to ascend to altitudes of more than 550 m above the ...

Feeding habit of Malaysian fruit bats

September 29, 2017

The lesser short-nosed bat, Cynopterus brachyotis, is the most common bat in Peninsular Malaysia and can be found in natural and logged forests, plantations, farms, villages, cities, and towns. Lesser short-nosed bats feed ...

Rare flying foxes shot in 'horrific' Australia attack

November 14, 2017

Dozens of rare grey-headed flying foxes have been shot in remote bushland near Australia's eastern coast, authorities said Tuesday as locals told of a "horrific scene" when the carcasses were discovered.

Improving safety for volunteer wildlife rehabilitators

February 3, 2016

Volunteer wildlife rehabilitators in Australia help protect the public from diseases carried by bats. A new study provides recommendations for future investment by state and territory governments that could reduce health ...

Secret lives of microbats investigated

February 21, 2017

The secret lives of microbats in the mid-west region of Western Australia are being revealed through a new research project at Murdoch University.

Recommended for you

Can China keep it's climate promises?

March 26, 2019

China can easily meet its Paris climate pledge to peak its greenhouse gas emissions by 2030, but sourcing 20 percent of its energy needs from renewables and nuclear power by that date may be considerably harder, researchers ...

In the Tree of Life, youth has its advantages

March 26, 2019

It's a question that has captivated naturalists for centuries: Why have some groups of organisms enjoyed incredibly diversity—like fish, birds, insects—while others have contained only a few species—like humans.

Cellular microRNA detection with miRacles

March 26, 2019

MicroRNAs (miRNAs) are short noncoding regulatory RNAs that can repress gene expression post-transcriptionally and are therefore increasingly used as biomarkers of disease. Detecting miRNAs can be arduous and expensive as ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.