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Mozambique Diary: Not all flies fly

Tsetse fly (Glossina sp.) from Gorongosa feeding on my blood. Luckily, tsetses in this area do not carry the dreaded sleeping sickness (but it does not make it any less painful).

Tsetse fly (Glossina sp.) from Gorongosa feeding on my blood. Luckily, tsetses in Gorongosa do not carry the dreaded sleeping sickness.

After a long hike in the scorching heat of the African savanna the cool, shady patch of tall miombo forest looked like heaven to us. I was in the southern part of Gorongosa, looking with a few friends for some elusive species of arthropods. But we were having little luck finding any and after several hours of strenuous walking the morale was low. As we stepped under the dark, inviting canopy of the forest, the drop in the temperature was palpable and we all relaxed, slowed down the pace, and the mood in the group immediately improved. But then, suddenly, somebody yelped “Ouch!” and at the same moment I felt a painful pin-prick at the back of my neck. Crap, tsetse flies! We looked around – they were everywhere. Clouds of them. We could see groups of dozens clumping on vegetation, taking into the air the instant they noticed the movement of our bodies. We ran.

A painting (undoubtedly the first and only) of a bat fly (Penicillidia sp.) burrowing in the fur of a Long-winged bat (Miniopterus).

A painting (undoubtedly the first and only) of a bat fly (Penicillidia sp.) burrowing in the fur of a Long-winged bat (Miniopterus).

Tsetse flies have long had a reputation for being one of the scourges of Africa, alongside malaria, crocodiles, and the plague of locusts. And deservedly so – some species of tsetses, all members of the genus Glossina, are vectors of nasty protozoans, including Trypanosoma brucei, the cause of the deadly sleeping sickness. Luckily for us, Gorongosa tsetses carry a different Trypanosoma species, T. congolense. This protozoan does not affect humans but unfortunately causes the chronic Nagana disease in cattle and horses, which explains the nearly complete absence of these animals around the park and in almost the entire region of central Mozambique. But knowing that tsetse bites are not going to kill us did not make them any more pleasant. Tsetses are large flies, about the size of a bee, and their skin-piercing mouthparts are much thicker than those of a mosquito. In other words, it hurts like hell when one jabs you with its proboscis, and you flail your arms like a madman to shoo it away while the fly escapes unharmed.

Members of the family Streblidae, such as this Raymondia sp., collected from the Hildebrandt's horseshoe bat (Rhinolophus hildebrandtii), often exhibit interesting adaptations in their wing morphology, such as the ability to fold them longitudinally along the back. This presumably helps them move swiftly in the pelage of their hosts.

Members of the family Streblidae, such as this Raymondia sp., collected from the Hildebrandt’s horseshoe bat (Rhinolophus hildebrandtii), often exhibit interesting adaptations in their wing morphology, such as the ability to fold them longitudinally along the back. This presumably helps them move swiftly in the pelage of their hosts.

But count yourself lucky. Imagine instead that you cannot shoo them away. You try to smack one but it runs, hides in your hair or some place where you are not able to reach, and it continues to bite. It only leaves your body to give birth somewhere in your house but then immediately runs back, guided by your scent and body heat. Oh, and imagine that this fly is the size of your fist (or a small puppy). Welcome to the world that bats are forced to live in.

Tsetses are members of a large group of flies, the superfamily Hippoboscoidea, all of which are exclusively hematophagous – blood is the only food that they are interested in. The tsetse family (Glossinidae) is the most basal (unsophisticated, one might say) member of this lineage of insects – they are always looking for a blood meal but never evolved the ability to stay with their tasty host. Bats are unlucky to have been colonized by two much savvier families of flies, the Nycteribiidae and Streblidae. These insects know the value of a good host and, once they landed on the furry back of a bat, they never leave it again. Over millions of years of coevolution with their mammalian hosts the bat flies have undergone a remarkable transition. From a free-flying ancestor, most likely very similar to today’s tsetse flies, emerged several lineages of highly modified, often completely wingless, spider-like creatures. Their body became flattened and very hard, making it almost impossible to squash them against the skin. In the family Nyctiberiidae the head turned into a small appendage that can be safely tucked away in a protective groove on the back and all traces of wings completely disappeared. These flies cannot survive for long outside of their host’s body and only feel at home when scurrying at an alarming speed in its dense fur. Their feet are armed with large claws that make it almost impossible to dislodge them from the hair of their host. They really don’t look like flies and when a friend spotted one on the body of a bat she called me to collect the bat’s “pet spider.”

In the closely related family Streblidae the wings may or may not be present, but even in the winged species the body is modified for squeezing through the fur, and members of the subfamily Ascodipterinae go even further in their commitment to the host. Much further. Once a female lands on a bat she sheds her wings and legs (yes, legs) and burrows head-first into the skin. Once there, her head and thorax sink into her own abdomen, and the skin of the bat overgrows her body. She becomes one with her host.

Penicillidia bat flies (Nycteribiidae) are some of the most unusual members of the order Diptera and hardly resemble their winged relatives. This individual was collected from a Long-winged bat (Miniopterus natalensis) in Gorongosa, Mozambique.

Penicillidia bat flies (Nycteribiidae) are some of the most unusual members of the order Diptera and hardly resemble their winged relatives. This individual was collected from a Long-winged bat (Miniopterus natalensis) in Gorongosa, Mozambique.

Female bat flies, like their relatives tsetse flies, are remarkably good mothers. The great majority of insects relies on what ecologist call “r-selection” in their reproduction – they lay hundreds or thousands of eggs, betting on one or two of them making it to adulthood. Bat flies, on the other hand, rely on “K-selection” – like humans, they prefer to invest a lot in a much smaller number of offspring, hoping that they will all make it to the reproductive age. They are larviparous – instead of laying eggs the female gives birth to a single, fully developed larva, which immediately turns into a pupa. While in her mother’s body, the larva feeds on “milk glands”, analogous to the mammalian mammary glands (if they were located in the uterus), and develops safely protected from the elements and predators. When the time comes for the mother to give birth she walks off the bat’s body and attaches the larva to the wall of the bat’s roosting place, usually a cave (which explains why bats that roost in rolled-up leaves and other less permanent places have fewer ectoparasites). Then she turns back and runs towards her host, guided by the smell and the heat of its body.

The recent Ebola crisis brought back the attention of the medical community to bats as potential reservoirs of the virus. Although there is no evidence that bats are in fact harboring the virus, there seems to be some correlation between instances of the outbreak and the presence of large numbers of bats in the affected areas. While reading the literature on both Ebola and bat flies I found it rather curious that nobody has tested bat flies for the presence of the virus – these are relatively very long lived (195 days on average) insects, who always stay (as pupae) at the roosting sites of bats, even when the hosts leave to forage elsewhere. They often move from one host species to another and, this point makes me really wonder why nobody has seriously looked at these flies as potential vectors, occasionally drop on and bite people. We know that they harbor a slew of pathogens – a recent study conducted in Gorongosa National Park on bats Rhinolophus landeri and Hipposideros caffer showed that flies living on these animals are vectors of Trypanosoma species that are ancestral to those that cause Chagas disease. Add to this the fact that one of the first cases of Marburg disease in Zimbabwe (caused by a virus related to Ebola) was caused by a bite of an arthropod (by default all unidentified bites seem to be classified by the medical community as “spider bites” and spiders in the area were tested, predictably unsuccessfully, for Marburg). It is far more likely that the bite was caused by a fly that fell off a bat.

A friend of mine recently expressed her dismay at “lowly” parasites. I beg to differ – if anything, parasites, including bat flies, are incredible examples of evolution at its best, organisms capable of both adapting to life in the most hostile of environments (the very substrate you live on wants you dead!) and resisting diseases that live inside your body. I cannot promise that I will not try to smack the next tsetse fly that lands on me but at least I promise that I will do it in the most respectful, considerate way.

Louse flies (Hippoboscidae) are close, equally modified for ectoparasitic lifestyle family of flies. This Lipoptena sp. was collected from a Nyala antelope while it was fitted with a GPS collar. Louse flies are parasites of large mammals and birds, and some are considered serious pests of sheep.

Louse flies (Hippoboscidae) are closely related to bat flies and equally modified for ectoparasitic lifestyle. This Lipoptena sp. was collected from a Nyala antelope while it was being fitted with a GPS collar. Louse flies are parasites of large mammals and birds, and some are considered serious pests of sheep.

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

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.

Mozambique Diary: Shooting bats

Leaf-nosed bats (Hipposideros sp.) in a cave of Cheringoma Plateau, Gorongosa National Park.

Leaf-nosed bats (Hipposideros sp.) in a cave of Cheringoma Plateau, Gorongosa National Park.

My entire last month was a blur of hectic activity, related mostly to the opening of the E.O. Wilson Biodiversity Laboratory in Gorongosa National Park. This kept me from updating the blog, but it was definitely worth it – the Lab is a fantastic facility that will serve as a research base to current and future scientists in the park, and as a center of advanced biodiversity education for Mozambican students for years to come (I just finished teaching its first African entomology workshop there, and it was great.) We are also creating the Gorongosa Synoptic Collection, which has the ambitious goal of documenting, over the next 15-20 years, all (or at least as much as physically possible) multicellular diversity of the park – I will try to post frequent updates from this effort. In the meantime, I would like to invite all biologists to come and work in Gorongosa – there is an entire universe of unexplored life out there, waiting to be studied and saved. Contact me if you are interested – Gorongosa wants your research projects, and we will help you make them happen.

Slit-faced bat (Nycteris cf. thebaica) from Gorongosa and a sonogram of its echolocation.

Slit-faced bat (Nycteris cf. thebaica) from Gorongosa and a sonogram of its echolocation.

One of the many benefits of having a permanent and safe logistical base in a place as biologically rich as Gorongosa is that I am not afraid to bring and leave behind my expensive high tech gear, and experiment with it. For months I had been dying to try out my high speed photography system, and finally was able to use it last month to shoot flying bats in the comfort of our lab. Now, bats have been photographed in flight by many, and the technology to do so has existed since at least the 1980’s. But, as far as I could tell, few had tried to take images of flying bats using the white background technique, made popular by the Meet Your Neighbours project, and I really wanted to try it.

An orange form of a Horseshoe bat (Rhinolophus landeri) from Gorongosa and a sonogram of its echolocation.

An orange form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa and a sonogram of its echolocation.

The setup for photographing bats in flight will be familiar to anybody who has ever worked with high speed photography: I used an external, very fast shutter (6mS response time, 10-50 times faster than the shutter in a typical SLR) mounted on a Canon 7D with a 100mm macro lens, triggered by two intersecting laser beams, and with four Canon flash heads that provided the illumination. Cognisys is a company that sells turnkey solutions for high speed photography, and their excellent StopShot system is what created the basis of my setup. The tricky part was to create a stage where the bats’ flight path was relatively narrow, allowing me to illuminate it properly. Last year I photographed bats in a cave, which was relatively easy, but gave me little control over the lighting. I needed to restrict their movement better, and decided to bring a large diffusion box that I would then turn into a flight chamber for the bats.

The box was about 1 m (3 ft) long, giving even the largest Gorongosa species ample room to fly. On the sides of the box I cut out two small windows (covered with thin, clear Perspex) that allowed the laser beams to go through. The front of the box had to remain unobstructed to the lens, but something had to stop the bats from flying out; I ended up using a large piece of thin glass (and had to adjust the flashes so that they would not reflect off the glass). But somebody had to put the bats in there, and it was not going to be me (one word – rabies!)

Leaf-nosed bat (Hipposideros caffer) from Gorongosa and a sonogram of its echolocation.

Leaf-nosed bat (Hipposideros caffer) from Gorongosa and a sonogram of its echolocation.

Luckily, I got help from Jen Guyton, a Princeton graduate student and a bat specialist, who is working on her Ph.D. in Gorongosa. Since capturing bats to get samples of their DNA (or rather the DNA of their prey) was part of her nightly routine, Jen was able to bring live bats to my studio and control them while I took the photos. Once all the technical kinks were ironed out, the system worked like a charm – in a few minutes I would get multiple shots of each bat, and then the animal was removed from the chamber unharmed.

A studio setup for photographing bats in flight: (1) Cognisys high speed shutter, mounted on Canon 100mm lens; (2) a laser and a laser beam sensor (an identical but vertically reversed set is positioned on the opposite side of the box).

A studio setup for photographing bats in flight: (1) Cognisys high speed shutter, mounted on a Canon 100mm lens; (2) a laser and a laser beam sensor (an identical but vertically reversed set is positioned on the opposite side of the box).

But some species turned out to be more difficult than others – members of the family Molossidae (my favorite bats) are not able to lift off from horizontal surfaces and thus could not fly in the box. Next month I plan to photograph them in the wild by combining this system with a UV light – I hope that the bats will be attracted to insects coming to the light (which they often are) and sooner or later will hit the laser trigger. Watch this space to see if it worked.

One final note – don’t try any of this at home! Nobody but professionals, vaccinated against rabies, legally permitted, and fully trained to handle live bats should ever attempt catching these animals. If you are interested in photographing bats, get in touch with a mammalogist at a nearby university or a conservation group that works with these mammals, and they may be able to help you. They are an awesome group of animals, but don’t risk their or your own life. Having seen Gorongosa bats’ unbelievably sharp, lyssavirus-carrying teeth in action, I now think of them as flying vipers – cool, beautiful and fast and, potentially, very deadly.

A grey form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa

A grey form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa

 

Mozambique Diary: Heroes, and what bugs them

Jen with her exciting catch

Jen with her exciting catch

One early morning, while on the Cheringoma Plateau, Jen “the Mammal Lady” Guyton came running into the camp. “We caught something really good in our traps!”, she announced breathlessly, sending the media team that was filming our expedition into a state of frenzied excitement. Everybody rushed to see the mystery animal, whose identity Jen refused to reveal. We scrambled through a spiny thicket and arrived at a place where she had set a large trap the night before. My imagination was running wild, and I was really hoping for a pangolin, or at least a baby aardvark. But the animal I saw was neither of these. At first, in the dim light I couldn’t quite make out the large mammal in the cage, and my first thought was of a small kangaroo, which would have been exciting if rather unlikely. “It is a pouched rat!”, Jen said proudly, and I felt all my hopes deflate like a punctured tire.

But my disappointment turned out to be grossly unjustified. To begin, the animal was actually very pretty. It was the size of a small cat, with a sweet face and slow, deliberate movements, quite unlike those of a house rat or any other rodent that I had ever seen. When Jen handed it a snack, it calmly ate it. Its tail was thick, half black and half white, which is a characteristic coloration of this species. Pouched rats (Cricetomys gambianus) are members of the family Nesomyidae, and thus not closely related to the rats that infest human houses, and derive their name from their ability to store food in large pouches in their cheeks. They can reach the weight of about 2 kg, and in some parts of Africa are hunted for their tasty meat.

Pouched rat (Cricetomys gambianus)

Pouched rat (Cricetomys gambianus)

In Mozambique, however, pouched rats play a very different role. The civil war of 1975-1992 has left many areas of the country infested with land mines, resulting in human casualties, and forcing people to abandon their land and houses. The removal of mines is an arduous process that normally requires the use of metal detectors or highly trained sniffer dogs. But in the late 1990’s Frank Weetjens, a Belgian mine-removal specialist, realized that pouched rats could make great mine detectors – they have an unparalleled sense of smell, and their calm nature and intelligence makes them easy to train. His organization APOPO set up a rat training camp in Tanzania, where young pups of pouched rats are taught to detect the smell of 2,4,6-trinitrotoluene (TNT), the main ingredient of land mines, and signal its presence to the trainer in exchange for a snack. After a 250-day long training the rats are flown into Mozambique, where they are used to systematically de-mine large areas still too dangerous for people to inhabit. Their efficiency in detecting land mines is nearly 100%, and their use in Mozambique has already allowed thousands of families to return to their homes and farmlands. It is not surprising then that in Mozambique they are known as Hero rats, a designation they fully deserve. In an even more amazing development, the pouched rats are now being used in Africa as sensitive and efficient diagnosticians of tuberculosis, a disease that affects many rural populations. Their incredible sense of smell allows them to differentiate between sputum of a healthy and an infected person at a rate and accuracy much higher than those afforded by traditional medical tests.

Epizoic earwig (Hemimerus sp.) on the fur of a pouched rat

Epizoic earwig (Hemimerus sp.) on the fur of a pouched rat

All this would be enough to make me worship pouched rats, but the animal we caught had a hidden entomological bonus. We had placed it a large container to take a few photos, and then we noticed dozens of large, brown insects running on its fur. One look and I immediately recognized them as something I had only read about before – they were parasitic earwigs! Earwigs are not insects that are usually thought of as something to be found on other animals, but members of the suborder Hemimerina are specialized parasites of rodents. They lack the large abdominal forceps of their free-living relatives and they are blind. Unlike other earwigs, they are also viviparous. On the body of the pouched rat they moved with an amazing speed, and their legs acted like clasps, allowing them to cling to hair and virtually swim through the mammal’s fur.

Epizoic earwigs (Hemimerus) lack the clasping cerci of their free-living cousins

Epizoic earwigs (Hemimerus) lack the clasping cerci of their free-living cousins

Adult parasitic earwigs (Hemimerus) have many nymphal characteristics, such as the lack of clasping cerci, wings, and wing musculature, suggesting that they are paedomorphic (reproductive stages that retain larval morphology.)
From the pouched rat’s perspective, having the earwigs is probably not too bothersome. These insects feed only on dead flakes of skin of the mammal, and thus act more as helpful exfoliants, rather than true parasites, and I also imagine that they provide an occasional snack.

All in all, the pouched rat in the trap turned out to be far more interesting than a baby aardvark would have ever been. (But I am still hoping to see one.)

An adult epizoic earwig (Hemimerus sp.)

An adult epizoic earwig (Hemimerus sp.)

Mozambique Diary: Golden bats

A colony of Lander's horseshoe bats (Rhinolophus landeri) – notice the orange hairs in the armpits of the flying male.

A colony of Lander’s horseshoe bats (Rhinolophus landeri) – notice the orange hairs in the armpits of the flying male.

Tomorrow marks the first official day of the Gorongosa Biodiversity Survey on the Cheringoma Plateau. All participating scientists are arriving, and the following morning we will depart for the first, northernmost site. But even before we get to those remote and unexplored areas, some of us have been already collecting interesting data.

Earlier today Jen Guyton, the expedition’s bat and rodent specialist, discovered a large colony of bats in an old, abandoned concrete water tank on the outskirts of the Chitengo Camp. It was too good of an opportunity to learn something new about bats of Gorongosa to pass by. Armed with a large butterfly net Jen had descended deep into the dark and rather odoriferous structure, and soon emerged triumphant with half a dozen bats fluttering in the net. She immediately identified them as Horseshoe bats (Rhinolophus), members of the family Rhinolophidae.

Two color morphs of Lander's horseshoe bats (Rhinolophus landeri) found in Gorongosa.

Two color morphs of Lander’s horseshoe bats (Rhinolophus landeri) found in Gorongosa.

These mammals get their common name from the characteristic, horseshoe-shaped noseleaf, an intricate structure on their faces that is the source of their echolocation signals. The ultrasonic signals of horseshoe bats are unusual in their relatively long duration and constant frequency, as opposed to more typical, short signals of shifting frequency found in most other insect-feeding bats.
Our bats turned out to be Lander’s horseshoe bats (Rhinolophus landeri), and the Chitengo colony had two color morphs of this species, one of which had a beautiful golden fur, which reminded me of that of the Amazonian Lion Tamarin. Lander’s horseshoes appear to feed mostly on moths, and can be identified among related species of the genus by tufts of distinct orange hair in the armpits of adult males (see photo).

In the coming days and weeks we will undoubtedly see more bat species and other amazing organisms. I will try to post updates from the field as often as I can, but it remains to be seen if my cellphone modem works in the areas were we will do our work. Stay tuned.

Mammalogist Jen Guyton examining a freshly caught Lander's horseshoe bat.

Mammalogist Jen Guyton examining a freshly caught Lander’s horseshoe bat.

Mozambique Diary: It’s good to have my gear back

To celebrate the miraculous recovery of my photographic equipment from the clutches of South African Airways, today I took my new Canon 400mm for a short spin around the Chitengo camp. I usually do not photograph birds and mammals, but there are so many of them around that it would be a shame not to point a lens at some.

This Yellow baboon (Papio cynocephalus) got in our cabin this morning and stole our bananas. Just a reminder to keep our doors and windows locked, we are on their turf here.

This Yellow baboon (Papio cynocephalus) got in our cabin this morning and stole our bananas. Just a reminder to keep our doors and windows locked, we are on their turf here.

There is a small colony of Village Weavers (Ploceus cucullatus) near my cabin. This male was finishing his nest and frequently displayed if any female was around.

There is a small colony of Village Weavers (Ploceus cucullatus) near my cabin. This male was finishing his nest and frequently displayed if any female was around.

African Pied Crow (Corvus albus) is a handsome, intelligent bird, but for some reason birders tend to ignore this species.

African Pied Crow (Corvus albus) is a handsome, intelligent bird, but for some reason birders tend to ignore this species.