From devils to superheroes: our complicated relationship with bats



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A “cloud” of Mexican freetail bats leaving their roost.
Wikimedia

Susan Lawler, La Trobe University

Review: Bat by Tessa Laird.


Did you know that the collective noun for bats is a “cloud”, or that in the first scientific classification of mammals, bats were placed close to humans because, like us, they have two nipples? The book Bat, by Tessa Laird, is full of similar tidbits that you will want to share with others. It is also engrossing, eloquent and beautifully illustrated.

Bat contains hundreds of delightful bat facts, but they are so grounded in context that the whole is much more than the sum of its parts. One cannot help but become intrigued and eventually transformed. I know I will never look at bats the same way again.

A chocolate wattled bat.
Flickr, CC BY

The author moves between Chiropteran (the scientific name for the bat group) biology, conservation, history, psychology and pop culture to capture the essence of bats, not only in all their marvellous diversity, but in our collective imagination.

Because their flight is erratic, bats are used as a symbol of insanity. Because they hang upside down and are active at night, bats can imply an inversion of normality. Their triumphant daily emergence from their caves can even represent rebirth.




Read more:
Why we shouldn’t be so quick to demonise bats


Bats suffer from not fitting comfortably into familiar categories. In Aesop’s Fables, the bat switched allegiance in the war between birds and beasts, so that when it was over the bat was shunned by both and forced to live at night. Their apparently hybrid nature was first noted by the Comte de Buffon in the 1780s when he wrote that the bat is an “imperfect quadruped and a still more imperfect bird”.

In Christian iconography, devils often have bat wings. Hans Memling, Hell, circa 1485.
Wikimedia

Early Christian iconography used bat wings for demons, to contrast with the bird wings that we see on angels. This may have something to do with the European prejudice against bats. When a sailor from Captain Cook’s Endeavour saw an Australian flying fox for the first time, he ran back to camp terrified, claiming to have met a real live devil.

Bats have been misunderstood throughout human history. It is, on reflection, extraordinary that we still use the phrase “blind as a bat”, knowing that they catch insects on the wing in the dark. Echolocation was not discovered until 1938, and because we cannot hear their calls, we did not know that bats basically spend their lives yelling at the world.

Even now, few people realise that bats are socially sophisticated; they share food, information, and maintain lifelong friendships within their colonies. They even engage in oral sex!

Yet bats are celebrated in some cultures. In China, bats are a symbol of luck, in part because the words “bat” and “luck” sound like each other in Chinese. They are also beloved in indigenous cultures from Mexico to Samoa to Papua New Guinea. Interestingly, cultures that venerate ancestors tend to love bats.

The demon queller Zhong Kui (鍾馗) and five bats representing the five blessings (五福).
Wikimedia

And just when you think that this book is about bats, it flips perspective and shines a light on humanity and our own foibles. Such as the second world war project to drop bats with incendiary devices strapped to them so they would crawl into the enemy’s roof cavities and explode.

Or when someone threw a live bat on stage and Ozzy Osbourne bit its head off thinking it was a toy – he was rushed to hospital for shots but apparently privately wondered if anyone would have noticed a change if he had contracted rabies.

There are pages dedicated to an analysis of the Batman superhero and his many incarnations, the Dracula story and its evolution since Bram Stoker’s publication in 1897, as well as more contemporary bat-inspired art.

For example, the 2015 installation in Federation Square in Melbourne, titled Batmania, consisted of 200 life sized flying foxes made from black plastic rubbish bags with holes burned in a filigreed pattern so that they looked like the stars of the night sky shining through. Each bat was juxtaposed with a collapsed parachute, as if to emphasise man’s inability to fly unaided. If we do not yearn for the freedom of flight, perhaps we dream of the immortality of vampires or the strength and anonymity of Batman himself.

Ben Affleck in Batman v Superman: Dawn of Justice.
IMDB

The bad reputation bats have in the human world has not been without consequences for them. Blamed for disease outbreaks from Ebola to rabies to SARS, bats have been killed in great numbers due to fear and ignorance. Their habitats are fragile and shrinking, and it is hard to overstate the planetary implications of their demise.




Read more:
Killer climate: tens of thousands of flying foxes dead in a day


Bats eat many tons of insect pests and are responsible for the pollination of some important and beautiful plants: mangoes, bananas, saguaro cactus. The conservation movement for bats has taken off in recent years, due in part to some excellent photography and a new appreciation of the cuteness of baby bats.

If you read this book you cannot fail to care more about bats, which I hope means that more people will become active in bat conservation. In the author’s own words:

The ConversationAs we have seen, bats have been variously associated with sexuality, diversity and sociability, combined with intuition and an ability to navigate through dark places, all of which seem like desirable qualities at the start of the twenty-first century.

Susan Lawler, Associate Professor, Department of Ecology, Environment and Evolution, La Trobe University

This article was originally published on The Conversation. Read the original article.

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Why we shouldn’t be so quick to demonise bats



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Justin A. Welbergen, CC BY-NC-SA

Justin Welbergen, Western Sydney University and Kyle Armstrong, University of Adelaide

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.


Read more: In defence of bats: beautifully designed mammals that should be left in peace


Australia’s weird and wonderful bats

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.
Justin Welbergen

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 bats 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.

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.

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)
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

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.


Read more: Not in my backyard? How to live alongside flying-foxes in urban Australia


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 bat species 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.

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.

Bats such as the grey-headed flying-fox (left) and the Christmas Island flying-fox (right) provide expensive pollination services for free.
Justin Welbergen (left); Carol de Jong (right)

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.

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

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.

“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.

Christopher Todd.

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 scratched or bitten, wash thoroughly with soap and water.
Arlington County

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.

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


Internet Archive Book Images/flickr

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.


Read more: Why bats don’t get sick from the deadly diseases they carry


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.

The ConversationGranted, 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.

Justin Welbergen, President of the Australasian Bat Society | Senior Lecturer in Animal Ecology, Western Sydney University and Kyle Armstrong, Past president of the Australasian Bat Society | South Australian Museum, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Not in my backyard? How to live alongside flying-foxes in urban Australia


Justin Welbergen, Western Sydney University and Peggy Eby, UNSW Australia

The conflict between urbanites and wildlife recently developed a new battleground: the small coastal New South Wales town of Batemans Bay, where the exceptional flowering of spotted gums has attracted a huge influx of grey-headed flying-foxes from across Australia’s southeast.

In response to intense and highly publicised community concern, federal Environment Minister Greg Hunt has announced he will seek an immediate National Interest Exemption to facilitate dispersal of these bats – a move that risks undermining legal protections afforded to this and other threatened species.

Similar conflicts are occurring elsewhere in NSW, such as the Hunter region, where some unscrupulous members of the public lit a fire in a flying-fox roost at Cessnock.

With the ongoing expansion of the human urban footprint, animals are increasingly confronted with urban environments. Human encroachment into natural habitats generally negatively affects biodiversity. However, urban landscapes can present wildlife with an irresistible lure of reliable food supplies and other resources. While urban wildlife can provide a range of benefits to health and wellbeing, it can also be cause for frustration and conflict.

Urban human-wildlife conflict is a growing area of management concern and scientific research. But the research suggests that the current strategies for addressing NSW’s conflicts between humans and flying-foxes might not have the intended results.

Flying-foxes increasingly find themselves in urban areas.
Justin Welbergen

Ruling the urban roost

Australian flying-foxes are becoming more urbanised, and the noise, smell and droppings from their roosts can have huge impacts on local residents.

A fundamental problem underlying current approaches to urban roosts is a lack of understanding of the extraordinary mobility of flying-foxes. They are some of the most mobile animals in Australia, with movements that range from foraging trips of up to 120 km in a single night to long-distance nomadism covering thousands of kilometres in a single year.

Nomadic movements of an adult female grey-headed flying-fox, tracked over a period of four years and currently at Batemans Bay.
John Martin & Justin Welbergen, unpublished

While roosts can remain active for decades, they are more like backpacker hostels than stable households, housing a constantly changing clientele that comes to visit local attractions. Roosts are connected into large networks through which flying-foxes move in response to changes in local food resources.

This explains the sudden influx in places such as Batemans Bay where preferred food suddenly becomes abundant. But it also highlights the importance of a national approach to flying-fox management and conservation.

Intense local flowerings of Eucalypts, such as spotted gums, produce copious amounts of nectar and pollen, which attract large numbers of flying-foxes and other species for several weeks. When a relatively small local flying-fox population that is tolerated by its human neighbours suddenly increases tenfold, it can place severe pressure on the local community.

Despite their transient nature, these influxes are often wrongly interpreted as population explosions, leading to calls for culling. In comparison, more humane tactics – such as using loud noise or vegetation removal to disperse the flying-foxes – can seem like a more balanced response. But does dispersal actually work?

Council workers in Charters Towers, Queensland, using ‘foggers’ to disperse flying-foxes from a local roost.
Australasian Bats Society

Shifting the problem elsewhere

There is now ample evidence to show that dispersals are extremely costly and can exacerbate the very human-wildlife conflict that they aim to resolve.

Most dispersals result in the flying-foxes returning the original roost as soon as the dispersal program ends, because naïve new individuals continue to arrive from elsewhere. Overcoming this can take months or years of repeated daily dispersal.

Other dispersals result in flying-foxes establishing new roosts a few hundred metres away, typically within the same urban environment in locations that we cannot control. This risks shifting the problem to previously unaffected members of a community and to other communities nearby.

Former flying-fox roost at Boonah, Queensland, that contained thousands of flying-foxes before it was destroyed in June 2014.
Justin Welbergen

While flying-foxes are often portrayed as noisy pests, they serve our economic interest by providing irreplaceable pollination and seed-dispersal services for free. What’s more, those same bats that annoy people during the day work tirelessly at night to maintain the health of our fragmented forests and natural ecosystems.

So it is in our national interest to manage conflict at urban roosts, by using approaches that balance community concerns with environmental considerations.

Flying-foxes perform irreplaceable ecological roles in our natural environment.
Steve Parish

To be considered “successful”, a dispersal should permanently reduce conflict to a level that is acceptable to the community without causing significant harm to the animals. However, dispersals are currently implemented at the local council level with little or no monitoring of the impacts in or outside the immediately affected area. This makes it hard to assess whether they have been successful.

For example, it is not uncommon for flowering to cease and flying-fox numbers to decline naturally during the period of active dispersal. This gives the community a false sense that a permanent solution has been achieved, when in fact the issues will recur the next time the trees blossom. There is thus an urgent need for urban roosts to be managed with properly defined and applied criteria for success.

Evidence-based management

Unfortunately, lack of research effort directed at “ugly” and “less popular” Australian animals means that very few evidence-based management tools are available to deal with contentious roosts.

Research targeting a few key areas would greatly help efforts to improve urban roost management. For instance, we do not know how flying-foxes choose their roost sites, which leaves us unable to design “carrot solutions” by creating more attractive roost sites elsewhere.

Intensive tree-flowering events are relatively infrequent and hard to predict. This means that it is difficult to prepare communities for a sudden influx of flying-foxes.

Furthermore, the acceptability of various flying-fox management options differs between sections of the community, so it is difficult to find optimal solutions. Social scientists are currently trying to help identify priority areas that promote long-term viability of flying-foxes while also easing conflict with humans.

The extreme mobility of flying-foxes means that a uniform federal approach for management is needed.
Justin Welbergen/WildPhotos.org

Local, state and federal governments continue to allocate considerable funds for dispersal responses, even though such actions are high-risk activities for local communities and are unlikely to provide long-term solutions. We argue strongly that targeted research is needed to better inform land managers and affected communities of flying-fox ecology and provide them with low-cost, low-risk, evidence-based tools for dealing with urban roosts.

Flying-foxes don’t care about legislative borders, and state-based responsibility for wildlife management leads to discontinuity in approaches between jurisdictions. While flying-foxes are being monitored at the national scale, this initiative needs to be combined with a uniform federal approach for managing flying-foxes in our human landscapes. Otherwise, conflicts such as those faced by the residents of Batemans Bay will continue unabated.

The Conversation

Justin Welbergen, Senior Lecturer in Animal Ecology, Western Sydney University and Peggy Eby, Adjunct Senior Lecturer, Centre for Ecosystem Science, UNSW Australia

This article was originally published on The Conversation. Read the original article.

Solomon Islands expedition seeks to conserve the extraordinary monkey-faced bat and giant rat


Ivy Shih, The Conversation and Tim Dean, The Conversation

The Australian Museum has announced a scientific expedition to the Solomon Islands to research a coconut cracking megabat and giant rat, with Professor Tim Flannery as one of the leaders of the program.

The expedition will be the most extensive survey of the oceanic archipelago since the 1990s and offers a rare opportunity to gain valuable insights about mammalian evolution in an isolated ecosystem.

The team will use a combination of DNA sampling, camera traps and traditional local knowledge to piece together information on the behaviour and distribution of the monkey-faced bat and giant rat. The results will influence the design of long term conservation efforts at the Solomon Islands.

The Galapagos of the Western Pacific

Map of the Solomon Islands
CIA The World Factbook/Wikimedia Commons

The Solomon Islands are a series of six major oceanic islands located in the Western Pacific Ocean. They are remarkable in that clusters of these islands have been largely isolated from major land masses throughout their geological history.

From an evolutionary biology standpoint, the Solomon Islands are invaluable as each island has developed a unique biodiversity independent of the others. Flannery has described them as “the Galapagos of the Western Pacific”.

“The islands are around 40 million years old and the fauna on each island in the chain are different,“ Professor Tim Flannery told The Conversation. “They have never been connected by a land bridge, so they have both been colonised separately either by water or flown there.

“It’s like the Galapagos Islands. Take a blank slate and let the species come in and populate it.”

There are five known species of monkey-faced bat (genus Pteralopex) and at least one species of giant rat (Solomys ponceleti) that are endemic to the Solomon Islands, and the expedition leaders hope to discover more species of both.

They are also the largest mammals on the Solomon Islands. However, sightings have been few and far in between, with current knowledge limited to museum specimens and anecdotes.

There is an urgent need to gain a greater understanding of the mega-fauna, with one species of monkey-faced bat (Pteralopex flanneryi, named after Tim Flannery) and one species of giant rat (Solomys ponceleti) classified as “critically endangered” by The World Conservation Union.

Basic questions about their biology, habitat and reproduction still remain a mystery. Flannery said that the expedition will answer those questions, which are crucial to starting conservation efforts.

“We need to start building from the ground up. To design an effective conservation method we’re in that crucial information gathering stage.”

Coconut cracking megabats

Specimens of the five currently known Monkey-faced bat species.
ivy Shih/ Australian Museum

What is known about the species of monkey-faced bats and giant rats found on the Solomons is that they have evolved characteristics unique to their species. In the absence of any other land based mammal, they have occupied an ecological niches no other bats or rats have ventured into before.

With a wing span of over a metre and a half, the monkey-faced bats are “megabats”, and are one of the biggest bats in the world. Their common name originates from their primate-like appearance.

“They dwarf the fruit bats around Sydney. The biggest ones are very striking, enormous black bats with big boxy heads,” said Flannery.

The monkey-faced bats in the remote Solomon Islands have evolved characteristic usually associated with monkeys. They have complex teeth and jaws so powerful it allows them able to crack green coconuts. The molars have a unusually large number of cusps and heavy incisors to break through the hard husks of the coconut. In addition the bats have a “double canine” with two big cusps.

Skull of a monkey-faced bat (left) showing the distinctive double canines of the species compared to the flying fox (right)
Ivy Shih/Australian Museum, Author provided

To Flannery’s knowledge, no other mammal has that kind of unique canine.

The Solmons giant rat weighs up to two kilograms and has reproductive behaviour unseen in other rat species. The last recorded sighting in 2006 of a female and young showed that they had only one young at a time.

However Flannery explained that in the absence of any mammalian carnivores, the monkey-faced bat and giant rat did not evolve any defence mechanisms. This proved especially disastrous for the species when feral cats were introduced.

“They’re a naive species. We’ve had accounts of people taking monkey-faced bats out of tree holes and they won’t even attempt to bite you. They are just so unaware of predation.”

The brink of a new era of discovery

In addition to locating the monkey-faced bat and giant rat, the team will also be canvassing the Solomon Islands for other undiscovered native mammals. Samples will also be sent to the Australian Museum Research Institute for molecular analysis to describe species scientifically. Local community involvement will also be an invaluable component.

“We are dealing with what are probably going to be fragmented specimens. There might be an old trophy skull hanging in a house for years or a jawbone. Fragmented DNA for analysis will be a big part of our work.”

Ornamental Comb worn by men from the Solomon Islands. Traditionally, the plant fibre wickerwork was woven using the wing bone of a bat.
Ivy Shih/Australian Museum Collection, Author provided

Designing a conservation program would also be crucial to ensure long term preservation of the Solomon Island biodiversity.

Despite the challenges, the research program could contribute much to the nature of mammalian conservation and research.

“The reality is that we are poised on the brink of a new era of discovery because there are so many species which have remained undetected. So there will be a new burst of activity where we will see many new species described and hopefully for the first time ever effective conservation,” said Flannery.

The Conversation

Ivy Shih, Editor, The Conversation and Tim Dean, Editor, The Conversation

This article was originally published on The Conversation. Read the original article.

Why bats don’t get get sick from the deadly diseases they carry


Michelle Baker, CSIRO

Bats are a natural host for more than 100 viruses, some of which are lethal to people. These include Middle Eastern Respiratory Syndrome (MERS), Ebola and Hendra virus. These viruses are among the most dangerous pathogens to humans and yet an infected bat does not get sick or show signs of disease from these viruses.

The recent Ebola outbreak in West Africa showed the devastating impact such diseases can have on human populations.

As treatments in the form of therapeutics or vaccines rarely exist for emerging diseases, future outbreaks of disease have the potential to result in similar outcomes.

Understanding disease emergence from wildlife and the mechanisms responsible for the control of pathogens in their natural hosts provides a chance to design new treatments for human disease.

The path to discovery

Until recently, bats were among the least studied groups of mammals, particularly in regard to their immune responses.

But even early studies of virus-infected bats provided clues that there may be differences in the immune responses of bats. It was observed that some bats were capable of clearing viral infection in the absence of an antibody response.

Antibodies are one of the hallmarks of the immune response and allow the host to respond more rapidly to subsequent infection when the same pathogen invades the body. The absence of a detectable antibody response within the bat was striking and drew our attention to the earliest stages of the immune response, called the innate immune system.

The recent sequencing of the first bat genome provided some of the first clues that the innate immune system may be key to the ability of bats to control viral infection. There is intriguing evidence for unique changes in innate immune genes associated with the evolution of flight, and bats are the only mammal capable of sustained flight.

Flight is energetically expensive and results in the production of oxygen radicals. In the research we speculated that bats have made changes to their DNA repair pathways to deal with the toxic oxygen radicals.

A number of innate immune genes intersect with the DNA repair pathways. These genes have also undergone changes, so it appears that the evolution of flight may have had inadvertent consequences for the immune system.

Bat super immunity

In humans and other vertebrates, infection with viruses triggers the induction of special proteins called interferon.

This is one of the first lines of defence following infection. It starts the induction of a variety of genes, known as interferon-stimulated genes. These genes play specific roles in restricting viral replication in infected and neighbouring cells.

Humans and other mammals have a large family of interferons, including multiple interferon-alpha genes and a single interferon-beta gene. People have 17 type I interferons, including 13 interferon-alpha genes.

Analysis published today of the interferon region of the Australian black flying fox reveals that bats have fewer interferon genes than any other mammal sequenced to date. They have only ten interferon genes, three of which are interferon-alpha genes.

This is surprising given that bats have this unique ability to control viral infections that are lethal in people and yet they can do this with a lower number of interferons.

Although interferons are essential for clearing infection, their expression is also tightly regulated. This is to avoid over-activation of the immune system, which can have negative consequences for the host.

The expression of interferon-alpha and interferon-beta proteins, which account for the majority of the antiviral response generated following viral infection, is normally undetectable in the absence of infection. It is rapidly induced following detection of a pathogen.

Yet we again see a difference in bats. The three interferon-alpha genes are continuously expressed in bat tissues and cells in the absence of any detectable pathogen. Bats appear to use fewer interferon-alpha genes to efficiently perform the functions of as many as 13 interferon-alpha genes in other species. And they have a system that is constantly ready to respond to infection.

Continual activation of the interferon response in other species can lead to over-activation of the immune response. This frequently contributes to the detrimental effects associated with viral infection, including tissue damage. In contrast, bats appear able to tolerate constant interferon activation and are continually primed for viral infection.

The bat approach in others

We are familiar with the important role bats play in the ecosystem as pollinators and insect controllers. They are now demonstrating their worth in potentially helping to protect people from infectious diseases.

The ability of bats to tolerate a constant level of interferon expression is poorly understood at the moment. But the identification of the unique expression pattern of interferons in bats is a first step in identifying new ways of controlling viruses in humans and other species.

If we can redirect other species’ immune responses to behave in a similar manner to that of bats, then the high death rate associated with diseases such as Ebola could be a thing of the past.


Peng Zhou was a co-author of this article. He’s a researcher in pathogen discovery and antiviral immunity, formerly employed at Duke–National University of Singapore Medical School and CSIRO.

The Conversation

Michelle Baker, Research scientist, CSIRO

This article was originally published on The Conversation. Read the original article.

In defence of bats: beautifully designed mammals that should be left in peace


Daniel Horton, University of Surrey

As a wildlife veterinarian, I often get asked about bats. I like bats, and I am always eager to talk about how interesting they are. Unfortunately the question is often not about biology but instead “what should I do about the ones in my roof?”.

With some unique talents and remarkable sex lives, bats are actually one of the most interesting, diverse and misunderstood groups of animals. Contrary to popular belief, they are beautiful creatures. Not necessarily in the cuddly, human-like sense – although some fruit bats with doey brown eyes and button noses could be considered so – but they are beautifully designed.

This couldn’t be illustrated better than by the discovery of the oldest known complete bat fossil, more than 53 million-years-old yet with a similar wing design to those flying around today. To put it in perspective, 50m years ago our ancestors were still swinging from the trees and would certainly not be recognised as human. But even then bats already had the combination of thin, long forearms and fingers covered by an extremely thin, strong membrane, which allowed them to master the art of powered, agile flight.

A flying fox shows off its 50 million-year-old wing design.
Duncan PJ, CC BY-SA

Soon afterwards, fossils record another game-changing adaptation in the evolution of most bats, and that is the ability to accurately locate prey using sound (what we call echolocation). These two adaptations early in their history gave bats an evolutionary edge compared to some other mammals, and allowed them to diversify into almost all habitats, on every continent except Antarctica.

Some bats are tiny.
Gillles San Martin, CC BY-SA

There are now more than 1,300 different species, divided among 26 different families (compared to fewer than 500 primate species). Indonesia alone has 219 different bat species.

It is not just a quantity though – the variety is astonishing. The thumb-sized bumblebee bat of Thailand is the smallest species, weighing just two grammes. And like other insectivorous bats, it can eat its own body weight in insects every night. At the other end of the scale, some large flying foxes have wingspans of well over a metre and, having lost the ability to echolocate, eat fruit and nectar.

The eerily pale ‘ghost bat’ roosts in the back of caves and will even eat other smaller bats.
quollism, CC BY

Everyone knows that some bats feed on blood, but despite the “vampire” myth, only three species actually feed on blood. And these haematophagous bats are only found in parts of South America. They also definitely don’t get tangled in your hair. Bats are far too good at flying.

If thus far I haven’t persuaded you to like bats, you must admit that they are useful. Bats defecate while regularly flying very long distances (up to 350km in one night), making them extremely effective at dispersing seeds. Add to that the fact that some fruit bats live in colonies up to 1m strong, and you can start to imagine their impact. So much so, they have been proven key in reforestation.

Another unappreciated and major role is as pest controllers. The sheer volume of insects that some bats species can eat makes them very effective at suppressing pest insects. Bats reduce the nuisance and disease threat of mosquitoes, and it has been estimated they save the US economy at least $3.7 billion every year through increased crop productivity and reduction of pesticide usage.

A Mauritian Tomb Bat with her pup
Frank.Vassen/flickr, CC BY

Despite their ancient design, they show some remarkable talents. One of these is shared only by several select animals. Bats are vocal learners – able to learn and then imitate sounds even in adulthood. This is likely important for the development of the complex social organisation seen in many bat species. Most surprising of all is the recent revelation that they are also members of an even more exclusive and less salubrious club: animals known to partake in fellatio during copulation.

Bats have had some bad press recently due to their association with infectious diseases, from rabies to Ebola. And they appear able to tolerate some viruses fatal to other species. If anything, that illustrates again why they should be respected, especially as various bat species are also endangered and therefore protected by law in many regions.

So my response to those interested in what to do about the bats in their roof? Leave them alone.

The Conversation

Daniel Horton, Lecturer in Veterinary Virology, University of Surrey

This article was originally published on The Conversation. Read the original article.

Papua New Guinea: New Guinea Big-Eared Bat Rediscovered


The link below is to an article that looks at the rediscovery of the New Guinea Big-Eared Bat.

For more visit:
http://theconversation.com/lost-bat-species-rediscovered-after-120-years-in-the-wilderness-26062