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Again and again I ask myself why people are afraid of bats. Adult humans weigh a hundred times more than the largest fruit bats. In fact of the fourteen hundred species of bat, the only bat known to deliberately harm people is the (highly social & altruistic) vampire bat (and, despite all of the hype, such incidents don’t seem to be particularly common).
Bats legitimately do harbor more sorts of viruses than other mammals and many of these viruses have proven to be zoonotic, yet as to whether they spread disease (or even are really the ultimate source of Ebola or Covid 19), the evidence is more exiguous. There are plenty of experts who push back against these claims. My whole article from the other day might have been contributing to anti-bat hysteria (which would truly sadden me since I love bats for their own sake…and for the many valuable roles they play in ecosystems across the entire world).
For what it is worth I don’t think that we fear bats out of some instinctual virus phobia (the way we instinctively recoil from snakes or spiders). The most cursory look at our culture reveals that Americans are not afraid of sugary foods or bad driving, yet these things are stupendous killers, wiping out more lives in a year than bat borne diseases have in all of history. But as Halloween rolls around we will see people shuddering at batfaces and then they trundle their kids out onto the street to collect candy!
My opinion is that bats are frightening because they are so closely adjacent to multiple things that people do fear. Bats are nocturnal (except for the Azores noctule, which we will exempt from this essay), and our fear of the dark is a primal part of all of us. Bats live in caves, treacherous landscapes of jagged rock, unseen chasms, and deep dark pools. When not at home in caves, bats are up in the night sky, another place where humans have only recently been able to go (and even with all of our technology it is still dangerous and problematic). Perhaps most damning of all, bats are close relatives to us primates and so many of our familiar features are right there in chiropteran physiology, but weirdly distorted in unsettling ways. Bats fall into the uncanny valley: they are sufficiently human to activate some of our social instincts, but then they are patently not human.
This is all speculation. Today’s entire post is an opinion about why people are afraid of bats and fear is hard to properly understand. We have no definitive answers and perhaps such answers are never forthcoming (particularly if fear of bats is based on a grab bag of adjacent fears with a soupcon of germophobia dusted on top)
The bigger point to all of this is that our fear of bats hurts bats..and it hurts us too. As I was writing this little essay, I found example after example of people overreacting to covid/rabies/ebola/SARS and killing bats in exaggerated wanton fashion. I will spare you the grisly details, but suffice to say, it was NOT the bats who came off as terrifying cruel monsters in these stories. People destroy bat habitats and root out bat colonies and kill the poor animals with poison, fire, and brute force, and why? The missing bats leave swarms of dangerous insects, orchards of unpollinated plants, and non-forests of unplanted seeds.
(This is to say nothing of the even greater–yet unintentional–killing of bats caused by habitat loss, climate change, and introduction of terrible invasive diseases which do kill bats such as white nose syndrome, a dreadful fungal scourge).
Batman decided to become BATman because he was afraid of bats. By becoming a bat he mastered that fear and turned it to productive ends (in the movies and comicbooks I mean, if we saw an actual billionaire dressing all dramatically and behaving crazy we would…uh…probably elect him as president). I wish we could learn a lesson from the Dark Knight and look into our hearts and see that bats are not the problem: fear and ignorance are the problems. If we can conquer those things, we can understand & defeat the diseases, fix the world, save ourselves and save the bats and be true heroes, not some made-up comic book nonsense. But I also worry that we are not currently doing well in our battles against fear and ignorance.
Welcome back to Ferrebeekeeper’s Halloween special feature concerning bats! If you like you can check out last week’s posts concerning bat mascots, Honduran white bats, and the Chinese good luck symbol Wu Fu. Bats are exceedingly wonderful and I love them…but where is the chilling Halloween horror?
Well, bats do have a dark side (at least to humans, when we eat them or intrude too far into their world). They are an infamous vector for zoonotic viruses which jump easily to closely related mammalian species. Although we are most attuned to this year’s worldwide pandemic, covid 19 (which seems not to have come from snakes, but from horseshoe bats) both the SARS and MERS epidemics were caused by bat-borne coronaviruses. Less memorably, bat coronavirues also jumped into the farmyard and caused a serious viral epidemic in China’s pigs. Bats are the natural reservoir for Ebola, Hendra virus, Nipah virus. A single bat can host many different viruses without getting sick. Because they live in close proximity in (sometimes enormous) colonies, viruses readily infect huge numbers of bats. Additionally bats are unlike other small mammals such as rodents and shrews in that they have long lifespans. Most bats can live 20 to 40 years (although, sadly, most do not because, as any World War I aviator could tell you (if any were alive), flying presents certain dangers).
All of this begs the question of why bats are so prone to viruses and yet also so resistant to their effects. Zoologists and Cell biologists are only beginning to unravel this puzzle, but what they have found presents a fascinating picture of the interplay between cellular biology and the physical characteristics of animals.
In the course of metabolizing, reproducing, fighting diseases and so forth, cells are sometimes destroyed in novel ways which release free DNA into places it should not be. This is potentially a big problem and animals cope with it through a mechanism known, sensibly, as DNA-sensing. Alas, this is about as far as I can reasonably describe this process, but you can check out a diagram which explains cytosolic DNA sensing machinery in humans below.
Uhhh…at any rate, among mammals bats have uniquely rigorous physiological demands due to the energy requirements of flight. The high-impact demands of flying lead to substantial cellular damage, but also preclude the solution other mammals adapt (which, as you can see above, is inflammation). If bats were prone to inflammation to the same degree as other placental mammals, they would lose their ability to fly. Instead they have lost various genes and have a more muted response to miscellaneous DNA. This diminished ability to clean up random intracellular DNA makes our fluttery friends more prone to all sorts viruses, yet they have found some other way to endure viruses without over-responding.
As you can probably tell, the cytological processes we are talking about seem to play huge and important roles in cancer, autoimmune disorders, and a host of chronic metabolic disorders like heart disease & diabetes. Not only would it be immensely beneficial to understand bats’ seemingly unique DNA sensing apparatus (and response) in terms of virology and epidemiology, it might bear fruit in many other branches of medical inquiry.
Alas, this sort of blue skies research (or should we call it dark skies research in honor of our nocturnal subjects?) is exactly the sort of thing which enormous companies are disinterested in and which the Federal government has turned its back upon. Fortunately (?), the Chinese government is extremely interested in finding out more about but-human zoonoses and has been diligently working to figure out more about DNA sensing and concomitant immune response in chiroptera. In fact, if the grotesque bowdlerization of the subject which I have presented in this post does not satisfy your curiosity, you can read a rather fine (albeit technical) Chinese article from 2018 about the subject.
For our special annual Halloween theme, Ferrebeekeeper usually features a subject which is scary or disquieting. However, since this year has featured an unprecedented amount of scary and disquieting content on its own, we are instead featuring a heartwarming subject which many people tragically misidentify as scary. I am talking about bats, one of my very favorite mammalian orders (and that is really saying something, considering that mammals are a class which includes all-time great orders like Proboscidea and Cetacea).
In subsequent posts we will talk about what bats are (they are near relatives of primates but their close taxonomical relationship to humans is obscured by their alien appearance and by the fact that cladists keep changing their understanding of the precise way we share ancestors). We will also talk about why people are scared of bats and about why bats are wonderful and useful. Additionally, due to this year’s tragic events we will highlight how bats need to be be treated with respect and carefully safeguarded (unless you would like a future with even MORE coronaviruses).
For right now though, let’s start out with a gallery of bat mascots (batscots?). Unfortunately, the fact that bats are a taboo animal to Christians means that, in the west, Batman and Bacardi are practically the only entities that chose the bat as a logo (well, them and the Louisville Bats, a minor league baseball team with a penchant for wordplay).
However there are a whole flock of lesser known (or completely unknown) bat mascots just waiting in the wings 9as it were). Check them out below
Good heavens! now that I look at all the wings and cartoon fangs, I wonder if I should have written about chiropteran biology before venturing out into popular culture. But whatever. There are some pretty endearing bats in all of that (particularly considering our culture’s unhappy relationship with bats as symbols). We will take the bat mascot as a starting point and explore the wonderful world of these amazing and precious animals in subsequent posts. Even if we can’t flit around the neighborhood we will make this a good Halloween… and hopefully we can save some bats too.
Mastiff Bat Vessel (Moche, 50-200 AD North Coast, Peru, Earthenware)
Longtime readers will remember that Ferrebeekeeper has a great fondness for the magnificent art and pottery of the Moche, a civilization noted for sophisticated agriculture, ultra-violence, and, um, magnificent art and pottery. The Moche lived in the rich coastal lands of what is now northern Peru. In the past we have written about their art of sea monsters and human sacrifice, and of waterfowl. Today we look at Moche bat-themed art.
Crescent-Shaped Ornament with Bat, C.E. 1 – 300 (from the Brooklyn Museum)
Double lobed whistling bat sculpture (Ca. 450 – 800 A.D.) the bat makes a chirping/whistling noise when water is poured out and air is blown in
Gold Bat Ornament (Moche)
Bats were beloved subjects of much pre-Colombian art (I owe everyone a post about the bat in Aztec art and myth). Although they were great artists, the Moche were scary people who were always sacrificing and garroting and flaying (more about that next week) and excarnating and hanging corpses everywhere. Yeesh… Perhaps unsurprisingly, the bats of Moche art are scary creatures with grimacing monster teeth and near-human expressions of malice and grief.
Early Intermediate (Moche IV), Mochica Molded stirrup-spout vessel, A.D. 500–700 Ceramic with red and white slip North coast, Peru
Moche IV ceramic stirrup spout bat form effigy vessel
Sadly we don’t know precisely what place the bat held in Moche mythology. In fact we don’t know anything about Moche mythology except what we can intuit visually. However there are lots of bats to visually interpret and it seems like a safe bet that they had a chthonic underworld meaning (as they do in Western art and culture). These bats are demons and monsters born of the dark night-side of the human spirit.
Moche Vessel (Early Intermediate period) Bat demon
Probably Moche (?) AD 200-500
All of these grimacing fanged bats with bared claws and anguished eyes make me think of the Moche people themselves—caught up in their centuries-long game of bloody worship and savage status. I wish I could help them, or even understand them, but they are gone. All we have are their skeletons and their beautiful dark art.
Moche – Pair of Gilt Bat Appliques. Loma Negra, Peru.
Gold Nasal Ornament with bat (Moche)
One of the problems with writing about living things is that there is a lot of troubling news from the natural world. If one writes about the many sad or perplexing issues affecting worldwide ecosystems, people get depressed and stop reading, but if one willfully ignores true problems…well, what is the point of observing and thinking about the world? I remember CNN’s online newspage used to have a Science/Nature header which was so consistently filled with news of species die-offs, ecological disaster, and worldwide blight that the whole science section was canceled. Now CNN has more room for “news” about Ashton Kutcher’s all fruit diet and a tech section with reviews of “cool gear” you can buy for your Superbowl party. Sigh….
All of which is a round-about way of apologizing for today’s upsetting (but extremely important) post concerning the mass die-off of North America’s bats. Wait! Please don’t go to other site to read about “Miley” Cyrus. Bats are actually really important. They are key organisms in ecosystems across the continent. If they all die, the rest of us mammals are also going to be in serious trouble
The culprit behind the bat deaths is a fungus, Geomyces destructans, which causes WNS–white nose syndrome. Despite its cartoonish name, white nose syndrome is a horrible death sentence for most temperate bats in North America. Geomyces destructans is a low temperature fungus (like the hideous specimens you find in neglected refrigerators). As the bats hibernate, powdery white fungus builds up on their little wings and faces. The poor itchy bats are awakened from hibernation and, because of the irritation, they cannot return to a suspended state. The little animals quickly burn up their energy reserves and die—to then become macabre bat-shaped clumps of fungus.
Geomyces destructans seems to have traveled to North America from European caves, probably on the boots or specialized equipment of spelunkers (strange troubled sportspeople who worm deep into the crushing dark of caves). Now that the fungus is in North America, it appears to be spreading by means of bat to bat contact. European bats seem to have a native resistance to the fungus, but American bats are unprepared for it and they have died in legion. Ninety percent of New Jersey’s bats are believed to have already died. As the plague moves to new colonies similar mortality is expected. Although the disease started in the middle of New York State, it has quickly spread along the East coast and it is moving west. Scientists worry that the pestilence could spread from coast to coast (although bats which live in warmer climes might be less susceptible to the low temperature fungus). Bats reproduce slowly—usually at a rate of one pup (or less) per year, so bat colonies cannot replenish like sardine schools or rodent colonies. Additionally the spores linger in caves even after all the bats have been killed.
I personally love bats. I find them endearing and beautiful (and relatable, since I have my own flighty nocturnal habits). Western culture has not been so kind and often equates the flying mammals with witchcraft, Satan, demons, and all other manner of underworld fiends (the Chinese, however, see bats as lucky—in fact one of the Eight Taoist immortals began his cycle of incarnation as a bat). A surprising number of Americans cleave to the old ways and smile at the horrifying curse that jackass cave explorers have unknowingly unleashed on our little chiropteran friends.
This attitude is a big mistake.
Anecdotally, the weather on North America has been worsening. Great storms pound our coasts, droughts scorch the hinterlands, and mighty cyclones appear everywhere knocking down forests. Imagine if, to compound these woes, vast plagues of insects descended upon our homes and crops.
Well, without bats, you won’t have to imagine. Bats are a principal predator of insects—especially nighttime insects like mosquitoes (but also a surprising number of agricultural and forest pests). Humans, being diurnal, underestimate bats, but insect-eating chiropterans eat 80% to 100% of their body mass in insects per night and they live in vast colonies (especially out west). Without bats we are liable to see great swarms of insects eat our crops and we will experience a resurgence of mosquito born ills.
The pallid bat (Antrozous pallidus) Photography by J. Scott Altenbach
An article in Daily Finance outlines some of the potential fall out of the great North American bat die-off (and if cold heartless financiers are worried about the environment, we know that something is really amiss). So how can we actually help the bats? The Federal government has allocated 1.6 million dollars to study the problem, but this is not a lot of money! Various agencies and organizations are attempting to curtail cave exploration and keep people from becoming a further vector for spreading the fungus. Making people aware of the problems bats are facing is also a useful step (which is why I am writing this). Most of all we need to care for bats before they are gone. Farmers, bankers, politicians, ecologists, and scientists all need to worry about our beleaguered friends. The mass die-off of honey bees has had a horrible effect on agriculture and forestry: the effect of a bat die off could be worse. But even more importantly bats are social mammals—like us. If suddenly 90% of them are dying off, it is a terrible portent as well as a horrible loss to the planet.
Frequent visitors to this blog will know my longstanding fascination with the mammals of Australia. Because of its long geographic isolation, the island continent was mostly free of eutherian (placental) mammals until very recently–meaning that magnificent non-placental oddballs such as platypuses, wombats, echidnas, quolls, and numbats had plenty of time and space to survive and flourish. However there is one order of placental mammals which proved to be a big exception to this general narrative. Bats are eutherian mammals which can fly. They reached Australia in the Oligocene (the Oligocene era lagerstätten at Riversleigh have yielded 35 species of microchiropterans) and have been very successful ever since.
The Spectacled Flying Fox (Pteropus conspicillatus)
Australia has 65 known species of bats, most of which are still fast tiny insect eating microchiropterans. In recent times though a few species of large fruit-eating megabats have showed up and made inroads into the continent. One of these megabats is the subject of this post–the spectacled flying fox (Pteropus conspicillatus), a big handsome bat which is widespread along the coasts of New Guinea and seems to have established a beachhead in Northern Queensland.
A pregnant female Grey-Headed Flying-Fox (photo by Ofer Levy)
Spectacled flying foxes are gregarious social animals which live in huge colonies high in the canopies of the rainforest. At night they feed on nectar and pollen from tropical blossoms or they squeeze the juice from fruits like mangoes and figs. Although large for bats, the animals weigh less than a kilogram (2.2 pounds) and their wingspan is about 1.2 meters (4 feet). They are called spectacled bats because of the strips of yellow-tan fur around their eyes.
Spectacled Bat Close-up (Photo from CSIRO Sustainable Ecosystems)
It is unclear when the bats came to Australia but the fact that they are indigenous to many of the islands around New Guinea indicates that they are powerful fliers. Additionally, like certain other fruit bats, the spectacled flying fox can occasionally sip sea water without any ill effects.
An orphaned baby bat being cared for at Batreach in Kuranda
Even though they are hunted as bush meat in parts of New Guinea, Spectacled flying foxes are doing fairly well in that part of their range. Unfortunately in Australia they are having trouble with deforestation and with the paralysis tick (one of the many horrifying toxic pests which abound in Australia). Kindly and good-natured Australians frequently rescue orphaned bats, and, when not reintroduced into the wild the captive bats can live over 17 years in captivity. The bats are social animals, so the lonely orphans often bond deeply with their human rescuers.
Sam the orphaned spectacled bat
How can some people not like bats? (This image was taken at Tolga Bat Hospital by Steve Amesbury to promote the noble cause of bat conservation: see DontShootBats.com)
Don’t shoot bats! (or otherwise hurt them!)
The Flower of Chiranthodendron pentadactylon
The Devil’s Hand Tree (Chiranthodendron pentadactylon) is an unusual evergreen tree from the cloud forests of Central America (Guatemala and Mexico). The tree grows up to 12 meters (40 feet) tall and has distinctive oversized leaves with ruddy metallic veins and fuzzy undersides.
Chiranthodendron is Greek for “hand-flowering tree” and pentadactylon means five fingered (which makes this tree sound like a grabby pterosaur or an early fish). There is good reason for the name though—as the common name indicates the distinctive flowers of this tropical tree look like demon hands. The five blood red stamens are shaped like clawed fingers–each of which has a double row of saffron yellow pollen running along it. As the flowers fade they curl into claws.
The pollinators of the tree are nectar sipping bats and perching birds (particularly orioles) which drink sweet nectar from the bowl-like petals beneath the stamen “claw.” Once the flower is fertilized it forms an extremely hard seed.
The tree was apparently revered by the Aztecs who knew it from a single grand specimen which grew alone in Toluca (in the Valley of Mexico). The lone tree was famous and venerated. Healers used parts of it to make medicine, but, despite—or because of—their respect, the Aztecs annually harvested every single flower off the tree to prevent it from germinating and producing others of its kind. However there were rumors about offshoots hidden in royal gardens (and in the private gardens of the tree’s tenders).
Extracts from the Devil’s Hand tree are reputed to have antimicrobial properties and to serve as heart stimulants—but I lack conclusive scientific evidence for these assertions. If you want to stimulate your heart you had probably find some other means of doing so.
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