African Bats: Conservation in the Time of Ebola

A guest post by Jen Guyton

Banana bats (Neoromicia nana) are tiny, insectivorous bats. Their name comes from the preferred roosting habitat of this species – furled leaves of banana plants.

Banana bats (Neoromicia nana) are tiny, insectivorous bats. Their name comes from the preferred roosting habitat of this species – furled leaves of banana plants.

The last fragile wing finally came free from the threads of my mist net. I sank into the sand on the riverbank, took a deep breath, and tugged off my yellow deerskin gloves. Eight cotton bags wiggled as they hung from the line that tethered my mist net to a tree. We’d gotten a swell of banana bats (Neoromicia nana), tiny creatures, no heavier than a large grasshopper, that are thought to roost in the furled leaves of banana plants. They had come in low over the river like a pack of tiny, flittering wolves, hunting the gnats and mosquitoes that hovered in a veil over the water. I’d had to work fast, because the longer the bats stayed in the mist net, the more tangled they became. Some even chewed their way through the nylon thread, escaping in a flurry of teeth and leaving behind a yawning hole for me to mend, its edges fringed with fragrant urine. Now, I just had to wait for my subjects to leave me a few fecal pellets in the cotton bags so that I could analyze their diet.

I looked with relief at Kaitlyn, my assistant for the day, as we took swigs of our beers. I watched the net billow and catch the moonlight, shining silvery-black like a benighted spider web, and listened to the sound of elephants crashing their way through the dense riverine vegetation in the distance.

Out of the corner of my eye, I saw Kaitlyn startle and look down. “I think something just peed on me,” she said, sounding perplexed. I shone my headlamp above her and was greeted by the glittering eyes and bulging cheeks of a large bat, hanging from the branch of the tree above us and happily chomping away on a piece of fruit. From the white patches below its ears and its fawn-colored fur I recognized it as an Epauletted fruit bat, a member of the genus Epomophorus.

A painting of the female Epomophorus wahlbergi that peed on Kaitlyn

A painting of the female Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi) that peed on Kaitlyn

I ran to grab my hand net, a long mesh bag on a circular frame with a handle. The bat was a dozen feet above us, and I didn’t have the handle extension sections, so I quickly duct taped the net to a mist net pole. I raised the net slowly, very slowly, sure that the bat would see me coming and take flight. But it continued to munch merrily, and it disappeared into the net with little more than a metallic peep! of protest. As I collected a fecal sample from it, Kaitlyn cleaned the urine from her clothes.

***

Little collared fruit bat (Myonycteris torquata) from Ghana, a species implicated in harboring the Ebola virus.

Little collared fruit bat (Myonycteris torquata) from Ghana, a species implicated in harboring the Ebola virus.

Stories like these have gotten me into trouble lately. “I study bat communities in Africa,” I’ll say, only to be greeted by wide eyes and mouth poised to speak the word that’s on everyone’s mind: Ebola.

Luckily, I work on the other side of the continent, thousands of miles from where Ebola has now taken almost 5,000 lives. My field site in Mozambique, on the southeastern coast of Africa, is safe from bat-borne diseases, as far as we know. But it’s no secret that bats have been implicated frequently in emerging zoonotic diseases – diseases of animal origin – that are now cropping up among humans: rabies in the Americas, Marburg virus in Africa, Hendra virus in Australia, and Nipah and SARS viruses in Southeast Asia are all harbored by bats.

The recent Ebola outbreak, too, has tenuous ties to our fluttering friends: scientists have found its antibodies in several species of West and Central African fruit bats. We can’t be sure, though, that they are “reservoir” species – organisms that consistently maintain a virus in their bodies without showing signs of illness. This would allow the bats to harbor Ebola, giving it the opportunity to spill over into humans. But, since we haven’t isolated live virus particles from the bats, all we know is that at some point in their lives,they were infected with or exposed to the virus that left its signature on their immune system.

So far, there’s no record of a bat transmitting Ebola to humans. Humans can get it from other humans, and we have solid evidence that people have become infected through ape carcasses, scavenged and eaten. People in parts of Africa eat bats too, but whether humans can catch the bug directly from bats is still a mystery. Some bat-borne diseases need to pass through what’s called an “intermediate” host – another species that amplifies the virus, allowing it to multiply and become more virulent – before humans can catch it. That is true of Hendra virus, which is found in Australian flying foxes. Contact with the bats poses little known threat to humans, but four people have died after interacting with sick horses. The horses, it seems, fed on fruits from trees where bats roosted.

A colony of Egyptian fruit bats (Rousettus aegyptiacus) from Nzerekore, Guinea, where many people have recently died of Ebola. This species has also been suspected of being the virus’ carrier. But this photo may be the proof of the bats’ innocence – despite spending several hours in the bats’ company and digging through their guano I have never become sick (PN).

A colony of Egyptian fruit bats (Rousettus aegyptiacus) from Nzerekore, Guinea, where many people have recently died of Ebola. This species has also been suspected of being the virus’ carrier but so far no live Ebola virus has been isolated from any species of African bats.

All of this adds to bats’ undeservedly bad reputation. Their mystical association with vampires, nocturnal habits, their seemingly erratic flight pattern, a slew of spooky superstitions, and now a misperception that bats are unusually disease-ridden have earned them a less-than-exalted place in the human consciousness. In some cases, this negative image arouses persecution. In 2007, hysteria stemming from a Marburg virus outbreak in Uganda led to mass extermination of Egyptian fruit bats, leaving heaps of them piled on the floor of the forest. This wasn’t an unprecedented reaction – people have been slaughtering vampire bats in Peru since the 1960s in an effort to control rabies, and a few years ago, the four human deaths from Hendra virus in Australia led to widespread culling of flying foxes.

Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi) from Gorongosa National Park in Mozambique

Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi) from Gorongosa National Park in Mozambique

But does reducing bat populations actually help reduce the risk of bat-borne diseases jumping to humans? Surprisingly, the answer is: probably not. In fact, there’s evidence that it could make things worse. In Uganda, the fruit bat extermination led to a much larger outbreak of Marburg, which is closely related to Ebola, among humans. As it turned out, fruit bats recolonized the caves from which they’d been exterminated, and the new population had a much higher prevalence of Marburg infection than the exterminated one. We’re seeing a similar effect in the Peruvian vampire bats – rabies prevalence is higher in populations that are subjected to culling by a poison called “vampiricide”, which preferentially kills adult bats. That’s probably because killing adults removes individuals that have already been exposed to the disease, making them immune. That allows “susceptible” juveniles, with no immunity, to proliferate, and the infection spreads like wildfire.

Fruit bats like bananas – even when they are being measured, photographed, or otherwise molested by a researcher.

It’s not clear whether bats really are different from other animals that could potentially carry diseases, or whether we’re just paying more attention to them now; there’s currently a debate raging among scientists about whether bats are special as disease reservoirs. Some say yes. This may be because many bat species are very social, which would allow pathogens to spread easily. Or, it could be that bats have a long evolutionary relationship with some virus families. Some scientists hypothesize that it’s linked to bat physiology: an unusual immune system, or the remarkably high body temperatures that bats experience during flight, could play a role in their ability to survive infections and, in the end, become reservoirs of pathogens.

Others argue that the numbers just don’t add up and that bats aren’t any more disease-ridden than other mammal groups. Given that bat research is on the increase it could be the simple result of a twisted treasure hunt: the harder we look, the more we find.

What we do know is that bats are special in a lot of other ways, and they deserve a boost in popular image. They’re the only mammals that have evolved true flight. They’re also one of the few groups, along with some whales, shrews, and birds that use echolocation – the ability to “see” a landscape using reflected sound waves. The combination of flight and echolocation allows them to fill a special role as nocturnal predators of aerial insects, with the potential to suppress insects like mosquitoes or some agricultural pests that aren’t active during the day. That does us humans an important service, and scientists have estimated that bats save U.S. agriculture $53 billion dollars in pest control every year. The high diversity of bats – they’re the second most diverse mammal group after rodents – allows them to fill a number of other important roles in ecosystems, such as dispersing the seeds of rainforest trees or pollinating flowers, including the agave used to make tequila.

We don’t yet know as much about bats and their diseases as we should, but the little evidence we do have suggests that killing bats will actually worsen the problem. It also suggests that the same things that are driving some bats toward extinction are also driving spillover events. Deforestation, for example, forces bats to find new homes in cities and increases the probability of their contact with humans. And eating bats gives their pathogens even easier access to people. We can reduce those risks if we protect bat habitats, halt culling efforts, and convince people to stop hunting and eating bats. None of these are trivial endeavors, but we need to try. In the time of Ebola, bat conservation is more important than ever.

Peters's epauletted fruit bat (Epomophorus crypturus) from Gorongosa National Park

Peters’s epauletted fruit bat (Epomophorus crypturus) from Gorongosa National Park

Treehoppers

Nobody really knows what the strange structures on the head of the Bocydium treehopper are for. They don't use them in courtship and seem pretty ineffective for defense.

Nobody really knows what the strange structures on the head of the Bocydium treehopper are for. They don’t use them in courtship and seem pretty ineffective for defense.

“I need to have my vision checked” was the first thought that popped into my head when my eyes met a treehopper of the genus Bocydium sitting on a thin branch in the Braulio Carillo National Park in Costa Rica, where I was researching several newly discovered katydid species. I had seen many mind-boggling organisms during my years as a tropical entomologist, but this thing looked like something that had just disembarked from a tiny interstellar spaceship. All the parts expected of a self-respecting insect were there – six legs, compound eyes, two pairs of wings – but what was the deal with the huge modernist sculpture on the head?

An ant can elicit the production of a droplet of honeydew by gently stroking the treehopper (Harmonides sp.) with her antennae.

For ants, a colony of treehoppers is like a pasture full of cattle. They protect the insects and collect their nutritious honeydew. An ant can elicit the production of a droplet of honeydew by gently stroking a treehopper (in this case a Costa Rican Harmonides sp.) with her antennae.

Treehoppers, members of the family Membracidae, are distant relatives of cicadas and aphids, and just like them they feed on liquids that flow through vascular tissues of plants. Such diet is extremely rich in carbohydrates, to the point that the excess must be expelled by the treehoppers. They do so in the form of honeydew, sugary water, dripping off the end of their abdomen, a substance that other organisms, ants mostly, find both delectable and worthy of fighting for. For this reason ants frequently form mutualistic relationships with treehopers, and defend them against potential predators in exchange for nutritious droplets. Some ants are even capable of asking for honeydew by gently tapping or stroking the treehopper’s abdomen, to which the insect responds by dispensing the drink. In addition to ants, certain wasps and flies also take advantage of this resource, but do not seem to repay in any way.

This mutualistic relationship with ants can influence the maternal behavior of some species. In many treehoppers the female guards the eggs and newly hatched brood, shielding them with her body and fending off predators. But if ants are constantly present, assuming the role of the brood’s guardians, then there is no need for her to stick around and protect her children. Instead, she can move on and lay another clutch of eggs on a different part of the host plant. Treehopper species that lead solitary life and don’t display maternal guarding of the brood are unlikely to attract ants’ protective interest as it is simply uneconomical for the ants to travel long distances to collect honeydew from a single insect. Thus, in some cases, developing nymphs of solitary species join “herds” of communal treehoppers, thus gaining the benefit of ants’ services.

Treehoppers are excellent parents – this female Thorn treehopper (Umbonia sp.) is shielding her eggs with her body; if necessary she can also use her powerful legs to kick potential predators.

Treehoppers are excellent parents – this female Thorn treehopper (Umbonia sp.) is shielding her eggs with her body; if necessary she can also use her powerful legs to kick and ward off potential predators.

But treehoppers are by no means helpless and, in the absence of ants, can defend themselves quite effectively using deceit, amazing body armor, and kickboxing (or at least an insect version of it). Nearly all species of treehoppers carry a massive, often intricately shaped and beautifully colored shield-like thoracic structure known as the helmet. In most cases its function is that of crypsis – many species resemble thorns, tiny leaves, or random bits of vegetation. Others use their helmet and bright coloration to turn into perfect replicas of stinging wasps, albeit they of course remain completely harmless.

Members of the tribe Hoplophorionini, however, go beyond such passive defense and have evolved powerfully muscled, spiny legs, which they are not shy to use on a wasp or any other predator that makes a mistake of straying too close. They kick and flap their wings, which is usually enough to drive away a predator several times their size. In those species where the female guards a large group of children, who usually position themselves in a long line all along a branch of their favorite plant, the insects employ a complicated language of acoustic signals – the nymphs can “talk” to the mother by sending substrate-borne vibrations, alerting her to an approaching enemy so that she can come running and ward the predator off. Acoustic communication is also used among adults to find mates, stake territories, or warn others about predators. Some species eavesdrop on other treehoppers to look for richer or safer pastures.

Two extreme examples of treehopper morphology – Membracis zonata, showing disruptive coloration that conceals the fact of being an insect, and Cladonota ridicula, a perfect imitator of a dead speck of vegetation.

Two extreme examples of treehopper morphology – Membracis zonata, showing disruptive coloration that conceals the fact of being an insect, and Cladonota ridicula, a perfect imitator of a dead speck of vegetation.

Entomologists had always assumed that trehoppers’ helmet was a simple outgrowth of the pronotum, or the dorsal plate of the first segment of the thorax. Pronotal modifications can be seen in other groups of insects (beetles or grasshoppers, for example), and thus it was only logical that treehoppers represented merely an extreme case of such a development. But a study published in 2011 by Benjamin Prud’homme and his colleagues (pdf) challenged this view. It provided tantalizing evidence that the awesome structures that treehoppers carry on their bodies are essentially a third pair of wings that had evolved to play a very different function. By carefully studying the embryonic development of treehoppers and mapping the expression of certain Hox genes (genes that control the development of serial structures, such as an insect’s body segments), they were able to show that the helmet of treehopers starts as a pair of tiny wing-like structures that later expand and fuse above the body. In some cases they even retain traces of hinges that are present at the base of normal insect wings.

And thus we know how, but not necessarily why. Some entomologists have suggested that the otherworldly shapes of Bocydium and other insane treehoppers are examples of ant mimicry, or simply serve to turn the body of an otherwise helpless insect into an equivalent of unpalatable fishhooks. But there might be another explanation – what if these structures are sophisticated satellite antennas and the treehoppers use them to stay in touch with the mothership? Probably not. Or maybe?

What possible function can these massive horns play in this Costa Rican treehopper Umbelligerus sp.?

What possible function can these massive horns play in this Costa Rican treehopper Umbelligerus sp.?

A portrait of a Costa Rican treehopper Poppea capricornis.

A portrait of a Costa Rican treehopper Poppea capricornis.

What to do?

This morning, in my bathroom, I was faced with a dilemma.

Spider_in_sink

And here are the results of the poll on what I should do about this sticky situation. It is heartening to see that the majority of voters would release the spider (which is what I did), but also rather sad that over 38% of respondents (discounting the 5% who were high while voting) would resort to violence (against either me or the spider). Votes

Mozambique Diary: Rescuing a Dragon

A guest post by Jen Guyton

In my lap was a specter, one of the most elusive animals in sub-Saharan Africa. I’d been waiting years to see it, and now it was weighing abrasively on my thighs like a sack of bricks stuffed into a giant pinecone. It wiggled and unfurled its roly-poly body just enough to reveal an eye like sticky caviar, its tongue whizzing in and out and reinforcing the illusion that this scaly orb was a dragon come to life.

Jen_Guyton_painting

But it was a warm-blooded, placental mammal, confirmed by the tiny body double that was furled in her grasp, suckling at the teats exposed on her underbelly. The mother and her pup were ground pangolins (Smutsia temminckii), one of eight species belonging to the mammalian order Pholidota, found only in Africa and southeast Asia. Though often called scaly anteaters, pangolins are unrelated to the Vermilingua, the suborder containing true anteaters. Actually, pangolins aren’t closely related to much of anything; these animals are unique, clinging to a long, isolated branch on the tree of life.

Safe at last – rescued from poachers, a Ground pangolin and her baby boy are going back to Gorongosa National Park to be released back into their habitat.

Safe at last – rescued from poachers, a Ground pangolin and her baby boy are going back to Gorongosa National Park to be released back into their habitat.

We were in Gorongosa National Park, Mozambique, and someone had told us about her. There was a man in a village across the river, the whispers went, selling her for the low price of 22,000 meticais (about $700 USD). Like rhinos, pangolins have fallen victim to a deeply-held misconception that their keratinous scales hold medicinal magic: that they can cure skin disease, reduce swelling, or even conquer cancer. I’ll tell you now: save yourself the money and the risk of jail time, and just chew on your nails – they are chemically and physiologically the same.

One day and a sting operation later, the pangolin was in my lap. Park rangers, working with the local police, arrested the poachers and rescued the animals. We were driving them out into the core of the park, where we’d release them, safely distant from grasping human hands. Though the pinecone plates of a pangolin’s back can and do stand up to being chewed on by lions, these animals are no match for a human that’s interested enough to simply pick one up and carry it off. Their only other defense is their smell, an indescribable odor that originates from a noxious acid secreted from glands below the tail.

I ran my hands along the pangolin’s scales. They were grooved and brittle-chipped, crooked and mud-splattered like fingernails that had seen many years of working with the land. In Asia, the scales of confiscated pangolins bear the circular scars of punches used for medicine. Even the artful hand of evolution, which had crafted this unique armor from a plush pelt, couldn’t save them.

Bipedal and armed with massive claws, a Ground pangolin could easily be confused with a carnivorous Jurassic raptor. But these gentle mammals feed exclusively on termites and ants, and their only defense is a thick armor of keratinous scales.

Bipedal and armed with massive claws, a Ground pangolin could easily be confused with a carnivorous Jurassic raptor. But these gentle mammals feed exclusively on termites and ants, and their only defense is a thick armor of keratinous scales.

As she unrolled herself from her fortress, a second head surfaced, tiny and pale. It was her male pup, the only one that will be born until he reaches sexual maturity in two years. He was born in captivity, a side effect of stress, and an unrealized bonus prize for the poacher. His scales were half-baked, pliable, and the dark shriveled stump of an umbilical cord poked from his round belly. He moved in the shivering stutters of an infant still unsure about the world.

As the pup crawled up my arm, the mother thrust out a hooked hand to right herself. Her claws, the length of my fingers, gripped my jacket like rusty nails and tore a gaping hole in the material as they bore into my side. I jumped, and she rolled back into a ball, her pup safely inside. These formidable sickle-claws are used to tear open termite mounds and ant nests, shredding the hard earth in search of scrambling adults and doughy larvae. The pangolin laps them up with its sticky-salivating tongue, longer than its own body and the longest relative to body size of all known mammals. Because pangolins lack teeth entirely, keratinous folds line their stomachs with inverse armor, grinding the insects to bits with the help of ingested pebbles.

Having spent a month in captivity, the pangolin, her baby tenuously clinging to her back. takes the first steps as a free animal.

Having spent a month in captivity, the pangolin, her baby tenuously clinging to her back, takes the first steps as a free animal.

We finally reached an appropriate site: far from the park’s perilous edges, the forest bulged above a tapestry of termite mounds. We set her gently on the ground, and waited.

Pup clinging to her back, she stood and sniffed the air, taking a few moments to orient herself to her new and safer home before choosing a bearing. Her scales clack-clacking, she ambled away on her hind feet like a drunken Velociraptor, tail out and claws curled against her chest. It’s hard to walk on all fours when you’ve got scythes for hands.

In Chinese mythology, pangolins are wayfarers. It’s said that they travel the world by digging through the core of it, tying the earth together with a vast underground labyrinth. In Cantonese, they’re called chun-shua-cap, “the animal that bores through the mountain.” I’d like to think she’s safely reached the Alps by now.

Text and artwork ©Jen Guyton 2014

If you would like to learn more about pangolins, and threats they face from the illegal wildlife trade, read a recent expository piece on the CNN website.

Safe under his mother's armor, a young pangolin will stay with her until his own scales are large and strong enough to provide protection from predators.

Safe under his mother’s armor, a young pangolin will stay with her until his own scales are large and strong enough to provide protection from predators.

Involuntary Bioslaughter and Why a Spider is Dead

“Hey, where is the spider post?”, you may be asking if you arrived at this page by following one of the thousands of links that sprung up overnight in the online media and social circuits. In the fine tradition of online publishing I took the liberty of pulling a “bait-and-click” switcheroo, and turning the hysteria surrounding the Goliath birdeater’s story into a teaching opportunity. And thus, please bear with me, and read this post to the end (where you will find the original post about the spider) before banging out an angry comment in ALL CAPS.

For some reason, probably related to the proximity of Halloween, my blog post about the Goliath birdeater spider received an inordinate amount of attention, and has been republished, reinterpreted, outright stolen, and vilified all over the Internet. This one post on my obscure blog is now receiving in excess of 120,000 unique visits every day, and comments are pouring in. Alas, most of them are somewhat less than positive, and I am beginning to wonder if I really am a “HORRIBLE person” who “will destroy the earth.” (I must admit that some of the trolls were touchingly tactful – they might have said ” F&*K you, a$$hole”, but they modified the foul words as not to offend my sensibility.) But why the vitriol?

Museum collections are priceless not only because of their role in scientific discoveries, but for igniting the fascination with the natural world in future generations of researchers, artists, and conservationist.

Museum collections are priceless not only because of their role in scientific discoveries, but for igniting the fascination with the natural world in future generations of researchers, artists, and conservationists.

You see, while talking to a reporter I explained that one of the specimens I describe in the blog had been collected and placed in a museum. This, combined with my comment of having seen this species only a handful of times, triggered a tsunami of self-righteous outrage at my murderous act which, according to the most vocal individuals, is bound to drive this species to extinction. In fact, I really fear for the Smithsonian Institution, this nation’s preeminent natural history collection. If a single spider collected by a scientist causes such an outrage then, surely, the 126 million specimens in its holdings will warrant burning it to the ground and crucifying all scientists working there.

But in all seriousness, why was the specimen collected? First, a bit of a background about the expedition to Guyana during which this took place. I was there with a group of biologists and Guyanese students at the invitation of the Ministry of Amerindian Affairs and the Environmental Protection Agency of Guyana. Our job was to conduct a comprehensive survey of animals and plants of the newly created Community Conservation Area, train Guyanese students in the methodology of biological surveys, and collect specimens for the Center for the Study of Biological Diversity at the University of Guyana. These specimens are used to both create permanent documentation of the species composition of a never before explored area of the country, and to train a new cadre of scientists and conservation professionals in identification and morphological diversity of organisms. And before you point out various alternative methods of documentation (photographs, sound recordings, non-destructive DNA samples), let me assure you that there is no substitute for the collection of physical specimens.

What about this particular spider? As I mention in the post below, Theraphosa blondi is indeed the largest spider in the world (although its legs are not foot long, as some media reported), and thus it makes a perfect specimen for teaching spider morphology. It is also a very common species, not protected or endangered, and collecting of a single individual poses absolutely no threat to its survival (a scientist picking up one spider is no different from a bird doing the same; if a stochastic event such as this can drive a species to extinction then this species is already doomed.) In fact, you can purchase Goliath birdeaters in many pet stores in the US or online for $20-100 a piece. But they are shy and elusive, and thus I was thrilled every time I saw one during a small handful of encounters with this species. Once the animal was properly euthanized and preserved, something that is never done lightly, it was carefully labelled and deposited in the collection in Guyana where to this day it serves as an important teaching tool. And, years from now, the same specimen may provide new data on spider anatomy, genetics, evolution etc. In addition to the spider, we also collected vouchers of 857 other species of animals and plants (excluding birds and large mammals), which are now deposited across various research institutions in Guyana, Venezuela, and the US.

The Endangered Katydid (Paracilacris periclitatus) – this species may already be extinct due to the loss of its habitat, but we know of its existence because I collected a few individuals and described the species.

The Endangered Katydid (Paracilacris periclitatus) – this species may already be extinct due to the loss of its habitat, but we know of its existence because I collected a few individuals and described the species.

Collecting and preservation of physical specimens is an integral, irreplaceable element of biological sciences. There is hardly a branch of biology that does not rely on the examination of organisms’ bodies (the only exception I can think of is ethology, and only some variants of it), be it for the purpose of their identification, understanding of the functions of their respiratory system, or the speed of transmission of neural signals. Museum collections, where specimens are preserved for future scientists, are a special, very important case. There specimens are often deposited not for a particular, clearly defined research project (such as when a geneticist examines thousands of fruit flies to measure the expression of a particular gene). Rather, collections serve as both a documentation of the current state of species composition in a particular time period or an area, or as a library of morphological and genetic diversity across a wide range of species. We cannot anticipate what questions will be asked, and answered, using specimens deposited in such collections. For example, the ban on the use of DDT, a horrible environmental pollutant, was based on the discovery made in ornithological collections that bird egg shells have been getting progressively thinner, thus leading to high mortality of birds, ever since the chemical began to be used. The spread of chytrid fungus that is wiping amphibian species across the globe was understood by examining specimens dating back a hundred years. Closer to my own research, the world’s only cave katydid is now listed as Endangered by the IUCN Red List and thus receiving a greater attention from conservationists, because I found 70-year old, unidentified specimens of this species, collected by a scientist who had no idea what a remarkable animal he was catching.

What do these beautiful animals have in common? You killed them. Or similar species. Our houses are death traps for countless organisms who are attracted to artificial lights and die inside. I found members of each of these species in the light fixtures of my house.

What do these beautiful animals have in common? You killed them. Or similar species. Our houses are death traps for countless organisms who are attracted to artificial lights and die inside. I found members of each of these species in the light fixtures of my house.

Can collecting specimens for scientific research threaten a species’s survival? The short answer is no, there is absolutely no evidence that any scientist has ever driven a species to extinction. Famous New Zealand 19th century ornithologist Walter Buller is sometimes accused of having collected birds to extinction, but a close examination of the numbers of specimens collected by him proves that his work had no impact on the birds’ populations; rather, his bird collection is now a sad repository of species exterminated in New Zealand by moronic, purposeful introduction of alien species and destructive agricultural practices on the islands.

And this is the key – species are never lost as a result of scientific collecting, but almost invariably because of the destruction of their habitat, or due to competition from alien species introduced by humans. And this loss of species is happening on an unimaginable scale – by some estimates 16,000 species quietly go extinct every year, some even before scientists have a chance to describe and name them. And this is why if I see something that may be new to science, even if I suspect that it might be rare and threatened, I will collect it and deposit it in a museum. Some years ago I found a new species of katydid in South Africa. I knew that its population was tiny and on the brink of disappearance. In fact, this species is now probably extinct. Not because I collected a few individuals, but because its only population was located in a tiny patch of a native yellowwood forest within a massive pine plantation, a patch that was already being cut down to be replaced by more non-native trees grown for timber. Had I not collected a few specimens of this animal, we would have never known it existed. Now, at least its tombstone has a name – Paracilacris periclitatus, The Endangered Katydid.

I could go on and on about why scientific collecting is needed, but I want to mention one last thing. Every single one of us is guilty of involuntary bioslaughter – we kill thousands of organisms without realizing that we do it. Look into the light fixtures of your house or the grill of your car, they are full of dead insects and spiders. That highway that you drive to work – each mile of it equals millions of animals and plants that were exterminated during its construction (and if you live in an area of particularly high endemism, California or New Zealand for example, its construction probably contributed to pushing some species closer to extinction). That tofu that you eat because meat is murder – it probably comes from Brazil, where massive soy plantations stretching from one horizon to another have replaced its once thriving rainforest and led to the disappearance of thousands of species.

A mile of highway kills more organisms that an entire generation of scientists. First during its construction, then when it turns into a conveyor belt to hell for any organism unlucky enough to step on or fly over it.

A mile of highway kills more organisms that an entire generation of scientists. First during its construction, then when it turns into a conveyor belt to hell for any organism unlucky enough to step on or fly over it.

It is very easy to fixate on an individual case of an organism being deliberately euthanized. We do it because it is convenient emotionally – it is much easier to feel superior when we can point a finger at somebody who does it consciously, even if for a good, justifiable reason, but we don’t like to think about those trillions of animals and plants that we kill by virtue of simply going to a grocery store.

And now, enjoy the story of the Goliath birdeater.


 

The sound of little hooves in the night

When I go out at night into the rainforest to search for katydids I don’t like to have any company. Not that I am particularly antisocial, but tracking skittish and cryptic animals is an activity that’s better done alone. I walk slowly, trying not to disturb anything and anybody, slowly scanning the vegetation and the forest floor in the light of my headlamp. Every now and then I turn the light off to fully immerse myself in the ambient sounds of the forest, which often helps me pinpoint a faint trill made by a katydid’s wings. A few years ago I was deep in the rainforest of Guyana doing just that – listening to the sounds of the night in a complete darkness – when I heard the rustle of an animal running. I could clearly hear its hard feet hitting the ground and dry leaves crumbling under its weight. I pressed the switch and pointed the light at the source of the sound, expecting to see a small mammal, a possum, a rat maybe. And at first this is what I thought I saw – a big, hairy animal, the size of a rodent. But something wasn’t right, and for a split second the atavistic part of my brain sent a ping of regret that I didn’t bring any companion with me on this particular night walk. But before that second was over I was lunging at the animal, ecstatic about finally seeing one of these wonderful, almost mythical creatures in person.

Goliath birdeater (Theraphosa blondi) from Suriname, displaying the full arsenal of its defenses – urticating hair, enormous fangs, and a loud hissing noise.

Goliath birdeater (Theraphosa blondi) from Suriname, displaying the full arsenal of its defenses – urticating hair, enormous fangs, and a loud hissing noise.

The South American Goliath birdeater (Theraphosa blondi) is the largest spider in the world. For all the arachnophobes out there this is probably a good excuse to pave over large swaths of the Amazonian rainforest, but for the rest of us this species is one of biodiversity’s crown jewels. Although far from being the largest member of the subphylum Chelicerata – this honor belongs to horseshoe crabs – Goliath birdeaters are ridiculously huge for a land arthropod. Their leg span approaches 30 cm (nearly a foot) and they weigh up to 170 g – about as much as a young puppy. They truly are Goliaths, but are they bird eaters? Alas, the truth is a bit less exciting. Although definitely capable of killing small birds, they rarely have a chance to do so while scouring the forest floor at night (however, there is some anecdotal evidence that they may feed on bird eggs if they run across a nest). Rather, they seem to be feeding on what is available in this moist and warm habitat, and what is available is earthworms – lots of them.

Goliath birdeater in its natural habitat in Suriname.

Goliath birdeater in its natural habitat in Suriname.

But how do they get to be so big? Apparently, according to one study (Makarieva et al., Proc. R. Soc. B [2005] 272), it has to do with their metabolic rate, which is lower than in the Goliath birdeater’s relatives. This allows it to function with lower levels of oxygen reaching its tissues and organs than those required by smaller, more active spiders. In other words, the bigger the body the more difficult it is to provide oxygen to all its parts if the metabolic rate is to remain constant. Regardless of the reason, because of its gargantuan size, the Goliath birdeater is probably the only spider in the world that makes noise as it walks. Its feet have hardened tips and claws that produce a very distinct, clicking sound, not unlike that of a horse’s hooves hitting the ground (albeit, admittedly, not as loud). But this is not the only sound this spider makes.

Every time I got too close to the birdeater it would do three things. First, the spider would start rubbing its hind legs against the hairy abdomen. “Oh, how cute!”, I thought when I first saw this adorable behavior, until a cloud of urticating hair hit my eyeballs, and made me itch and cry for several days. If that wasn’t enough, the arachnid would rear its front legs and open its enormous fangs, capable of puncturing a mouse’s skull, and tried to jab me with the pointy implements. The venom of a birdeater is not deadly to humans but, in combination with massive puncture wounds the fangs were capable of inflicting, it was definitely something to be avoided. And then there was a loud hissing sound. For a long time the source of the sound was a mystery, but now we know that it is produced by “setal entanglement” – some of the hairs (setae) on the legs are covered with microscopic hooks that scrape against other, feather-like setae, producing the loud warning hiss.

With the leg span of nearly 30 cm, the Goliath birdeater is an animal that should be treated with respect, even though it is pretty much harmless to humans.

With the leg span of nearly 30 cm, the Goliath birdeater is an animal that should be treated with respect, even though it is pretty much harmless to humans.

A couple of years after my first encounter with Theraphosa blondi I was in South America again, walking alone at night in the rainforest of Suriname. Suddenly my foot brushed against something big and moving, and I nearly tripped. I froze, expecting a snake. “Nah, it’s just another Goliath birdeater. Aren’t you a cutie pie?”

Update 1: You can now purchase high quality prints of all images appearing in this post – just click on the image. For commercial use please contact Minden Pictures with inquires regarding licensing of these photos.

Update 2 (28 Oct. 2014): It has been over a week since the Goliath story hit the news (isn’t it like 2.3 years in the Internet Time?), and it is probably good to let it go and refocus on another worthy cause. Thus I am closing the comments under this post, but feel free to express your opinion on any other story on this blog (but please stay topical – if you would like to tell me what you think about the spider story, or me personally, just email me). The question of scientific collecting is clearly a polarizing one but, unlike such important questions as whether God uses a Mac or Windows, it actually has one, right answer – we need scientific collecting (pdf) and it serves a wide variety of beneficial causes (pdf).
The comments that I have received demonstrate an enormous need for more science education and outreach, especially in the light of some of the most brutal ad hominem attacks coming from persons who probably would label themselves liberal and well-educated. It was rather entertaining to see the breadth of insults thrown at me, including being called, for some reason, “sexist” (interestingly, the same lady who called me that also suggested that I should “get laid, quickly” – I am puzzled, to say the least.)
Please keep visiting my blog, I am always happy when my stories raise awareness of the beautiful world of invertebrates and other underappreciated organisms, and the conservation work that I and my colleagues have been engaged in for many years. In the end, this experience was a positive one – if I can make people care about a single spider then maybe there is hope for the rest of the natural world?
A Goliath birdeater from Guyana, the first individual of this species that I ever encountered. Her opisthosoma (abdomen) is nearly bold because most of the urticating hairs ended up in my eyes and mucus membranes – now I know better than to put my face too close to these animals.

A Goliath birdeater from Guyana, the first individual of this species that I ever encountered (possibly T. stirmi). Her opisthosoma (abdomen) is nearly bald because most of the urticating hairs ended up in my eyes and mucus membranes – now I know better than to put my face too close to these animals.

A new voice in the chorus

A pair of Jumping Bush Crickets (Orocharis saltator) from Massachusetts. Females have long, needle-like ovipositors, which they use to lay eggs deep into the stems of plants.

A pair of Jumping Bush Crickets (Orocharis saltator) from Massachusetts. Females have long, needle-like ovipositors, which they use to lay eggs deep into the stems of plants.

Yesterday evening, right before the weather turned nasty, as I stood on the deck over my garden I suddenly caught a sound wave, one that I immediately recognized but had never before heard around my house. I ran to grab my recorder and was able to capture a snippet of the call. Seeing me pointing my microphone towards his house, a neighbor approached me warily, inquiring if I am trying to find the property line. I explained what I was doing and he left, satisfied in his knowledge that I am just feeble minded, and not trying to sue him for his land.

The call was that of the Jumping Bush Cricket (Orocharis saltator), a species I first encountered a couple of years ago in Cambridge, MA. Since then I have been looking for other places where this pretty animal might live, but never expected to find it in my backyard. It is a species that belongs to the chiefly tropical subfamily Eneopterinae, and makes a fine addition to the chorus of crickets around my house, which now includes 12 species:

Jumping Bush Cricket (Orocharis saltator)
Handsome trig (Phyllopalpus pulchellus)
Say’s trig (Anaxipha exigua)
Carolina ground cricket (Eunemobius carolinus)
Allard’s ground cricket (Allonemobius allardi)
Striped ground cricket (Allonemobius fasciatus)
Two-spotted tree cricket (Neoxabea bipunctata)
Snowy tree cricket (Oecanthus fultoni)
Spring field cricket (Gryllus veletis)
Fall field cricket (Gryllus pennsylvanicus)
House cricket (Acheta domesticus) (introduced)
Eastern ant cricket (Myrmecophilus pergandei)

Sonogram of the Jumping Bush Cricket (Orocharis saltator); click here to listen to the recording.

Sonogram of the Jumping Bush Cricket (Orocharis saltator); click here to listen to the recording.

A male Jumping Bush Cricket (Orocharis saltator).

A male Jumping Bush Cricket (Orocharis saltator).

 

On the benefits of random collecting

A female Cederberg cave katydid (Cedarbergeniana imperfecta) preening her antennae.

A female Cederberg cave katydid (Cedarbergeniana imperfecta) preening her antennae.

In 1911, after a short and apparently unsatisfying stint as a lawyer, Keppel H. Barnard left his native London and joined the staff of the South African Museum in Cape Town. First a mere lab assistant, he quickly ascended the ranks, in 10 short years reaching the position of the museum’s director, which he held until his retirement in 1956. Barnard’s life was dominated by two seemingly opposite passions. One was the study of aquatic animals, and during his productive career he laid the foundations of modern African ichthyology, carcinology, and malacology. But I probably would have never even heard of him if it wasn’t for his second obsession – mountaineering. In September 1925 his insatiable desire to scramble pointy rocks lead him to the ragged peaks and caves of Cederberg, a mountain range of red, Ordovician sandstone, about 150 km North of Cape Town. Once there, his zoological predilection kicked back in, and made him look into every nook and cranny to collect specimens for the museum. In narrow caves known affectionately as the Wolfberg Cracks he encountered large, spider-like insects, with spindly, striped legs and 6-inch antennae. But neither he nor anyone else knew what to make of them, other than that they might have been katydids.

Sandstone spires above Wolfberg Cracks, one of the few caves where cave katydids can be found.

Sandstone spires above Wolfberg Cracks, one of the few caves where cave katydids can be found.

For 70 years those specimens had sat in a dark corner of the museum until, after a string of my increasingly incessant letters, they were packed with a bunch of other unidentified material and shipped to me, then a young student of entomology working on a revision of southern African katydids. One glimpse at the specimens and I knew that they were special. Not surprisingly they were new to science — an always welcome but not unexpected occurrence. But the fact that the insects had been collected from caves was intriguing — no other katydid had ever been found in such a habitat. Could those be the first such animals? Their morphology certainly seemed to suggest it. Extremely long appendages and pale coloration are the hallmarks of troglophiles, organisms living in caves, and the new katydids fit this pattern.

Resembling large spiders, cave katydids exhibit typical morphological characteristics of cave animals, which relay mostly on tactile information when moving around.

Resembling large spiders, cave katydids exhibit typical morphological characteristics of cave animals, which relay mostly on tactile information when moving around.

To add to the mystery, all specimens were immature, and I could only speculate about what the adults might have looked like. I published a formal description of the new katydids, giving them the scientific name Cedarbergeniana imperfecta (immature katydid from Cederberg; now I wish I had named them after Barnard), but ever since I have been dying to find out more about their behavior and biology. Do they really live in caves? What do they eat? Can they sing? Are they solitary, like virtually all katydids, or do they live in groups, like cave crickets?

Cave katydids are gregarious, found in multi-aged groups of 20-30 individuals.

Cave katydids are gregarious, found in multi-aged groups of 20-30 individuals.

In the years that followed I have been able to visit Cederberg many times, and collected a lot of data about their biology. Yes, they truly are cave dwelling katydids, the world’s only, and yes, they are highly gregarious, often found in clusters of 20-30 individuals of various ages. The caves they prefer are cold, maintaining the chilly temperature of 12°C (54°F) throughout the year. Their habitat cannot be occupied by bats or hyraxes, which probably quickly do away with the tasty, surprisingly very slow-moving insects, thus limiting the number of available caves (interestingly, when exposed to higher temperatures they become phenomenal jumpers). I know now what sound they produce – a short, ultrasonic click. All their close relatives (katydids of the tribe Aprosphylini) produce long, continuous trills, but such a call would probably cause a lot of reverberation in a cave environment and thus make it difficult for a female to locate a singing male. I also know what they eat, a mystery that had bugged me after seeing the nearly sterile interior of the cave – they leave the cave at night to forage on grasses and other plants growing at the mouth of the cave. This behavior makes them, in technical parlance, trogloxenes.

Last month, during a short visit to Cederberg with my friend Jen Guyton, I approached Wolfberg Cracks with some trepidation. For one, it is a tricky climb and, having witnessed another friend tumble down the mountain and break several bones while looking for cave katydids, I did not want the same thing to happen to me or, especially, Jen – it would be hard to explain why young females who accompany me to the cave always end up falling off cliffs. But I was also worrying about the katydids themselves. Corey Bazelet, my collaborator at the University in Stellenbosch, and I have recently completed the IUCN Red List assessment of South African katydids, and the Cederberg cave katydid unquestionably ranks as Endangered. It is known only from a tiny handful of locations in the Cederberg Mountains, a possible relic of colder climates of the Pleistocene, having found shelter in the cooler environment of the caves. With, what now seems to be unavoidable global climate change, and an already well-documented warming up of southern Africa, I fear that its days are numbered. But, luckily, today cave katydids are doing very well. Jen and I found them to be thriving; I even found an additional, small cave where I had not seen them before.

A male nymph and adult female of Cederberg katydid (Cedarbergeniana imperfecta).

A male nymph and adult female of Cederberg katydid (Cedarbergeniana imperfecta).

We climbed back down safely and stopped at a little gift shop at Sandrifft, the highest vineyard in Africa and the legal owner of the Wolfberg caves, and picked up a few bottles to toast to the survival of K.H. Barnard’s incidental discovery, the result of his random collecting that lead to the description of the world’s only cave-dwelling katydid and now, with its proclamation as an Endangered species, its increased protection. If the chances of the katydids’ survival are in any way related to the amount of toasting, they will be just fine.

The contrasting coloration of the cave katydids allows them blend in among the colorful rocks of Cederberg during their rare forays outside the caves.

The contrasting coloration of the cave katydids allows them blend in among the colorful rocks of Cederberg during their rare forays outside the caves.

A cave katydid cleaning his foot; their tarsi are incredibly sticky, allowing these insects to walk upside down on the smooth celing of their cave.

A cave katydid cleaning his foot; their tarsi are incredibly sticky, allowing these insects to walk upside down on the smooth celing of their cave.