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Mozambique Diary: Amphisbaenians

Most people would hardly look twice at this small, pink “worm”, but this amphisbaenian (Chirindia swynnertoni) from Gorongosa probably looks like the now extinct ancestor of all snakes.

Most people would hardly look twice at this small, pink “worm”, but this amphisbaenian (Chirindia swynnertoni) from Gorongosa probably looks like the now extinct ancestor of all snakes.

Having drawn the short straw at the phenotypic lottery I have always felt a special kinship with creatures that most people dismiss as too small, too creepy, too unattractive. Because these are (I tell myself) the hallmarks of the truly interesting organisms, ones that have followed the less-trodden paths of unusual specialization, remarkable adaptations, evolutionary ingenuity.

One such organism, about the existence of which I learned as a young child from an old zoology textbook, was Bipes, an amphisbaenian. It was a chimeric, strange creature, with the appearance of a pink snake, but equipped with a pair of shovel-like legs at the front end of its long body. There was a striking resemblance between that creature and a picture of a dragon that I had seen in the illustrated edition of the Old Testament from my Sunday School (which, incidentally, offered its classes on Monday nights), and I was instantly hooked.

Although it looks like a soft and squishy, the amphisbaenian’s head hides a strong skull that allows it to push through even the hardest soil.

Although it looks soft and squishy, the amphisbaenian’s head hides a strong skull that allows it to push through even the hardest soil.

Amphisbaenians are reptiles, but so unusual that for the longest time they were considered a separate order of these animals. For one, they look nothing like a vertebrate – the last couple of times that somebody brought me an amphisbaenian they were under the impression of having collected an earthworm (unlike Bipes, most species are legless.) Their annulated body is usually pink or covered with irregular, white and dark blotches, a clear indication that these animals don’t care about how they are perceived by others. And for a good reason – why bother with the looks if your entire life is spend underground and you yourself are blind. Better to invest the energy that would have been spent on the irrelevant appearance into things such as a thick skull and powerful thoracic muscles that will allow the animal to push effortlessly though the soil in search of prey.

My assistant Ricardo Guta looking for insects and other animals in the habitat of the Gorongosa amphisbaenian.

My assistant Ricardo Guta looking for insects and other animals in the habitat of the Gorongosa amphisbaenian.

Recent phylogenetic studies revealed that amphisbaenians are not a separate, primitive order of reptiles, but rather a highly derived, supremely modified lineage of lacertiform lizards. It is very likely that the next step in this transition to a subterranean lifestyle was the complete loss of limbs and girdles, a dramatic reshaping of the skull, the loss of eyelids and, eventually, the emergence of a brand new group of animals, the snakes. In fact, the most basal (primitive) snakes, the Typhlopidae and other related families, look remarkably like the amphisbaenians.
A few days ago I was in the southern part of Gorongosa, checking out sites for the second biodiversity survey of the park, and there, in a dry, crumbling log, I found a beautiful little amphisbaenian, Chirindia swynnertoni. This species is rarely seen, and thus I promptly followed a recommendation of a field guide to amphibians and reptiles of East Africa: “Anyone finding a worm-lizard [amphisbaenian] should take it to a museum.” I still haven’t had the heart to preserve it for the Gorongosa Synoptic Collection, and instead I have been watching it for days, transfixed by its amazing ability to squeeze into the hardest soil with the body that looks like an overcooked string of pasta, and with a baby-pink face of a newborn. It has been feeding on termites and ant larvae, crushing the insects with its tiny yet powerful jaws. And I find it fascinating (and somewhat rewarding) that from so seemingly unassuming a beginning came a lineage of animals that has terrified the human psyche since the time of Eden.

Gorongosa amphisbaenian (Chirindia swynnertoni)

Gorongosa amphisbaenian (Chirindia swynnertoni)

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: The House of Spiders

A guest post by Edward O. Wilson

The skeletal remains of the Hippo House, once a busy restaurant and observation point.  Orb weaver (Nephilengys cruentata) from the Hippo House.

The skeletal remains of the Hippo House, once a busy restaurant and observation point.

Each spider in the Hippo House was sheltered in a tubular retreat, a behavior typical of all species in the genus Nephilengys.

Each spider in the Hippo House was sheltered in a silken, tubular retreat, a behavior typical of species in the genus Nephilengys.

At the end of a long rutted road in the park sits a conspicuous artifact in the midst of wilderness. Built in 1970, the Hippo House was the vantage point, the antigo miradouro, from which well-heeled tourists, cool drinks in hand, watched wildlife herds as they grazed over the vast floodplain grassland below. Today the herds are back, but the house is a seldom-visited ruin. During the Mozambique civil war, almost all the buildings of Gorongosa National Park were torn down or blown away, leaving behind a few remnants scarred by bullets. The house had been reduced to a shell of its original self.

When I first visited the Hippo House, Mozambique was in the middle of the winter dry season. Other than along the watercourses, the vegetation of Gorongosa was brown and withdrawn. Insect life was still abundant, but harder to locate. I had been told that spiders, big ones, were abundant at the house, but I was quite unprepared for what I found. The interior of the ruined building was powder dry. Its floor, stanchions, and ceiling were windblown and coated with dust. No vegetation reached in from the outside, and except for a few small geckos resting on the pillars, there was no immediate sign of life of any kind. Instead, torn webs and long single threads of silk dangled from the ceiling like ghostly decorations in a haunted house. They swung gently back and forth in the occasional light breeze. No other movement or sound came from the seemingly empty space.

An unlucky katydid that flew into a web under the Hippo House is immediately killed and wrapped in silk by a female orb weaver.

An unlucky katydid that flew into a web under the Hippo House is immediately killed and wrapped in silk by a female orb weaver.

Where were the spiders I expected? Not one could be seen. But I knew they must be there someplace, alive, perhaps watching us. The idea of a hidden arachnid horde ready to rush out made me uneasy. Soon I saw something else: round objects plastered onto the ceiling. They were dusty and silent. My companions and I picked up a stick lying on the ground outside that was long enough to reach the ceiling, and tore two of the pouches apart. They proved to be silken egg pouches, undoubtedly made by spiders but now dry and empty; we were obviously not in the breeding season. The spiders themselves stayed hidden. Where were they? I grew more apprehensive.

We saw other, much larger, oblong pouches scattered over the rough eroded ceiling. At the tip of each was a circular entrance opening to a hollow interior. Using a flashlight and looking straight down the chamber, we could see what lay within. There at the rear of each pouch crouched a large spider, facing outward, its fangs, eyes, and the front of its tightly bunched legs visible. I wanted to see a specimen well enough to identify it, but hesitated. I was, to be frank, afraid of these crouched and waiting spiders. I suffer from mild arachnophobia. This spooky place was the setting of an arachnophobe’s nightmare.

The golden orb-weaver (Nephila senegalensis) is one of the largest spiders of Gorongosa. Its name comes from the beautifully golden coloration of its silk.

The golden orb-weaver (Nephila senegalensis) is one of the largest spiders of Gorongosa. Its name comes from the beautifully golden coloration of its silk.

We selected one of the pouches and poked at it in and out, but the spider stayed tight inside. One of my companions then took charge. He tore open the pouch and shook the inhabitant out into a transparent plastic bag. At last I could see what had lain within. The spider was heavy-bodied, the size of a thimble. When it suddenly spread its spiny legs, its width almost tripled.

I had solved the mystery of the spider house, at least in theory. The creatures in the silken bags were orb weavers, members of the spider family Nephilidae, called golden orb weavers, and, I later learned from an arachnologist, the species is Nephilengys cruentata. Some species of nephilids and the closely related araneids hide in retreats next to their webs; others remain in the centers of the webs. But how could there be so many spiders of this one species crowded together? Why are there no other creatures of any kind? The explanation I believed to be immediately clear. The floor of the lower level of the spider house is a layer of concrete. The interior is abnormally dry. Because the lower level cannot be invaded by any vegetation, few if any other forms of insect or arachnid life can live there. Yet flying insects undoubtedly fly through the wide-open space of the lower level, in through one side and out the other. A few might settle there to rest. The fate of most or all is the same: spider food.

Orb weaver (Nephilengys cruentata) from the Hippo House.

Orb weaver (Nephilengys cruentata) from the Hippo House.

My imagination was roused by this bizarre little world, but more so by my own reaction to it. When I took the captured spider back to Chitengo Camp, I found I was unable to make a specimen of it. That would mean fishing the monster out of the cellophane bag and working it into a bottle of preservative. So I simply opened the rear window of my room and dumped my captive live onto the ground below, where it would at least have a chance of making its way to a tree or building and spinning a new silken retreat.

I remember vividly the incident that made me an arachnophobe. I was eight years old. It was late summer, and I was exploring a vacant lot near our house. There were several full-grown female orb-weaving spiders in the high weeds, likely the common garden spider (Araneus diadematus), sitting in the center of their webs. I could not resist getting close enough to see all the details of one spider’s body. When I was about a foot away, it began to jerk back and forth in a menacing manner. I thought it was preparing to jump out and onto me. I ran. If that were not bad enough, I soon afterward saw a movie, the name of which I have long forgotten, in which a man is trapped in a cave. Blundering around, he becomes tangled in spiderwebs that are hung all around. Spiders, really big ones, climb down toward him, and . . .

Aversions and phobias of this kind, with the latter an extreme response causing panic and cold sweats, can be imprinted with as little as a single brief episode. They are rarely caused by a frightening experience with a knife, a gun, an automobile, or any other modern contrivance that can injure or kill. On the other hand, they easily and quickly follow a frightening experience with one of mankind’s ancient perils: snakes, spiders, wolves, heights, running water, and closed spaces. During millions of years of human prehistory, it has paid in a major Darwinian way to have quick, decisive response to the things that can kill you.

So I have forgiven myself for the wavelet of fear and revulsion I felt about the harmless denizens of the spider house. Let me make further amends by stressing that people are mostly safe amid what remains of living nature. We conquered the man-eaters long ago by destroying almost all of the big predators willing and able to hunt humans. They survive in our stories and in our legends of monsters. We imagine them silently emerging from caves and swamps, easing up from unexplored depths of the sea, or drifting down unseen from above. Walk into or swim in any wild habitat remaining on Earth, maintain the same level of caution you would on a city street, and you will be far safer than in most urban environments. Use common sense: don’t swim with crocodiles; don’t paddleboard among seals where great white sharks have been seen; and above all, never, ever run up to a mother grizzly bear with cubs to take a better look. Your greatest risk in the wild is from insect-borne disease—malaria, dengue, leishmaniasis, yellow fever—and these can be deadly if untreated. But they are transmitted chiefly among people. They can be easily avoided, and in any case pose less risk to you than the mélange of pathogens passing directly from person to person in human settlements.

The scary but harmless spiders in the Hippo House, and all the other animal species of wild environments like those of Gorongosa, are instinct-guided. They rigidly follow life-and-death routines formed during millions of years of evolution. Their lives are finely tuned and fragile in ways that are blessedly unthreatening to human beings.

Text Copyright © 2014 by Edward O. Wilson, Photographs Copyright © 2014 Piotr Naskrecki

Read more about the biological complexity and restoration of the fascinating ecosystem of Gorongosa National Park in “A Window on Eternity”, a new book by E.O. Wilson, with photos by P. Naskrecki (Simon & Schuster 2014).

Tarantulas, known in southern Africa as baboon spiders, may look frightening but are generally harmless. Their main line of defense is not their venom, but tiny urticating hairs that cover the entire body.

Tarantulas, known in southern Africa as baboon spiders, may look frightening but are generally harmless. Their main line of defense is not their venom, but tiny urticating hairs that cover the entire body.

Piotr Naskrecki and Edward O. Wilson in Gorongosa National Park, Mozambique.

Piotr Naskrecki and Edward O. Wilson in Gorongosa National Park, Mozambique.

 

Mozambique Diary: A single breath that changed the planet

The sound of an early ancestor of this lungfish (Protopterus annectens) taking it first gulp of air signified a pivotal moment in the history of life on Earth. The emergence of this behavior, along with the development of four limbs, set the stage for the conquest of terrestrial habitats by vertebrates, and the evolution of all tetrapods.

The sound of an early ancestor of this lungfish (Protopterus annectens) taking its first gulp of air signified a pivotal moment in the history of life on Earth. The emergence of this behavior, along with the development of four limbs, set the stage for the conquest of terrestrial habitats by vertebrates, and the evolution of all tetrapods.

About 400 million years ago, in the Devonian, in what was likely a shallow, freshwater pond in some tropical part of the world, a fish made a sound that started a dramatic chain of events, one that culminated in you and me being born. The sound was that of air being sucked in, as the fish lifted its mouth above the surface of the water, desperate to replenish falling oxygen levels in its bloodstream. Soon, gulping for fresh air became a necessity, as the gills failed to supply enough oxygen from the warm, muddy waters to sustain the animal’s activity. Its bladder, which up to that point helped maintain buoyancy for swimming, started to function as a gas exchange organ, an early version of lungs. At the same time, the fish’s pelvic and pectoral fins grew sturdier, and their connection to the rest of the skeleton more capable of lifting the body above the substrate. With these two steps the stage for the vertebrate conquest of land was set. We probably will never know when and where exactly this momentous transition took place, but we are pretty sure of what that fish looked like. And I am staring at it right now, as it looks back at me from the bottom of my beer cooler.

The Southern African lungfish (Protopterus annectens brieni)

The Southern African lungfish (Protopterus annectens)

Ever since I first set foot in Gorongosa National Park in Mozambique I have been obsessed with meeting my oldest living vertebrate cousin, the lungfish (Protopterus annectens). Despite its unassuming physique, reminiscent of a large eel, the lungfish holds a special place in the history of life on Earth. Biologists have always suspected that the lungfish gave us insight into the origin of terrestrial vertebrates, but only last year a massive molecular phylogenetic analysis (pdf) , based on 251 (!) genes, proved that the lungfish is a sister taxon to all tetrapods – amphibians, reptiles, birds, and you, and the rest of mammals. Previously that place was reserved for the coelacanth, a marine fish of equally ancient provenance, but now it appears that the coelacanth is an earlier offshoot of fishes that went its own, equally interesting, if less pivotal, way.

My first encounter with the lungfish took place a couple of months ago, when I ran across a fisherman who had caught a couple of these animals. Alas, by the time I met him they had been killed and gutted, leaving me heartbroken and even more obsessed. This time I made it abundantly clear to anybody who would listen that I wanted a live lungfish, and last week a fisherman from the village of Vinho finally delivered one into my hands.

In Gorongosa National Park lungfish are common, if rarely seen, inhabitants of seasonal water pans. During the dry season, when the pans evaporate, the lungfish burry themselves in the mud and estivate for several months. During this period their metabolic rates drop by about 60% and gas exchange is done entirely through their lungs.

In Gorongosa National Park lungfish are common, if rarely seen, inhabitants of seasonal water pans. During the dry season, when the pans evaporate, the lungfish burry themselves in the mud and estivate for several months. During this period their metabolic rates drop by about 60% and gas exchange is done entirely through their lungs.

It is difficult to describe the nearly religious reverence I felt when I saw my first live lungfish. Here was an animal that, I am pretty sure, looked like something I would see in the ponds of the early Paleozoic, long before first amphibians, even longer before dinosaurs. As I watched the lungfish slowly moving in my cooler, it suddenly lifted its head above the water and loudly inhaled a big gulp of air. I don’t think I will ever be able to forget the sound of it.

The lungfish does not have fins like other fishes. Rather, it has two pairs of whip-like appendages that act as weak, but very much functional legs. In 2011 an interesting experimental study (pdf) demonstrated that the pelvic fins are used by the lungfish in a fashion very similar to that of the land animals’ hind legs, for both walking and bounding. This in turn casts a new light on some early Devonian fossil tracks that were thought to have been left by primitive amphibians – in fact, they probably are those of semi-terrestrial lungfish ancestors. The development of articulated limbs with fingers (digited limbs) no longer seems to be the prerequisite to the conquest of land.

If you think that this looks like walking that’s because it is. Lungfish use their pelvic fins in a way very similar to that of a tetrapod’s legs – the distal part of the fin becomes a “foot” and the fins produce both walking and bounding motions.

If you think that this looks like walking that’s because it is. Lungfish use their pelvic fins in a way very similar to that of a tetrapod’s legs – the distal part of the fin becomes a “foot” and the fins produce both walking and bounding motions.

The more we study the lungfish the more fascinating it becomes. It is now clear that this animal holds the secret to the development of tetrapod ears, and they were the first to develop enameled teeth, the kind we, mammals now have. The lungfish is also superbly adapted to the harsh seasons of the southern African savanna, and can burry itself in the ground and survive for months out of water, hidden from the hot sun in a muddy cocoon (stories abound about African farmers digging out live, large fish from their dry fields.) Its dependence on atmospheric oxygen is so strong that the lungfish will drown if not allowed to breathe above the surface of the water. Its strongly reduced gills are virtually non-functional, but during the lungfish’s larval development are external and feathery, resembling those of the salamander larvae.

A portrait of the Southern African lungfish (Protopterus annectens brieni) from Gorongosa.

A portrait of the Southern African lungfish (Protopterus annectens) from Gorongosa.

In Gorongosa lungfish are common in seasonal pans and rivers of the park, feeding on a wide range of aquatic invertebrates, smaller fish, and frogs. As they are highly territorial, it is likely that almost every body of water on the plains has at least one of these remarkable animal. It is a shame that they are never seen by the visitors to the park – in my opinion the lungfish surpasses in its importance and a fantastical set of features any other vertebrate of Gorongosa, lions and elephants included, and I vow to make it my mission to spread the knowledge of its existence.

Last week, on March 27th, the E.O. Wilson Biodiversity Laboratory was officially opened, a culmination of my and many other people’s dream. More about the Laboratory soon, but I thought it fitting that the first vertebrate sample for our synoptic collection is a small snippet of the lungfish’s caudal fin, preserved for future DNA barcoding. The animal itself is being released back into its habitat, and I hope that this was not the last time that I looked into the eyes of my grand…grandfather’s twin brother.

Resembling an oversized salamander, the lungfish has four distinct limbs, a long tail, and only remnants of gills. The gills are virtually non-functional and the fish will drown if not allowed to breathe above the surface of the water.

Resembling an oversized salamander, the lungfish has four distinct limbs, a long tail, and only remnants of gills. The gills are virtually non-functional and the fish will drown if not allowed to breathe above the surface of the water.

Mozambique Diary: Sibylla

A portrait of the Precious Sibyl mantis (Sibylla pretiosa) – it is easy to get the impression that this insect really thinks.

A portrait of the Precious Sibyl mantis (Sibylla pretiosa) – it is easy to get the impression that this insect really thinks.

These days, if God speaks directly to you, be it about the precise date for the end of the world or his opinion about somebody else’s sexual preferences, you are either a crazy nut or a Westboro Baptist crazier nut. Ancient Greeks, clearly more open minded about such things, referred to a woman with powers to prophesy God’s actions with a much nicer-sounding honorific – Sibyl. Perhaps the 19th century Swedish entomologist C. Stål saw some of that craziness in the facial features of a gracile praying mantis from southern Africa, and christened it Sibylla pretiosa – the Precious Sibyl. Looking at this remarkably anthropomorphic insect it is indeed easy to get the impression that some strange thoughts are percolating in its brain.

The Precious Sibyl mantids (Sibylla pretiosa) are usually found high on the branches of savanna trees.

The Precious Sibyl mantids (Sibylla pretiosa) are usually found high on the branches of savanna trees.

I first encountered Sibylla many years ago in Zimbabwe, amazed at the sight of large mantids, nearly ghost-like in their slender built and pale coloration, that were zipping up and down smooth tree trunks. Last year I once again found Sibylla while collecting insects high in the canopy of a large Combretum tree in Gorongosa National Park. Alas, it was a tiny nymph. This month, however, while in Gorongosa during the peak of the rainy season, Sibyllas were plentiful on tree trunks and at the lights of the Chitengo Camp.

A male Sibylla cleaning his antennae.

A male Sibylla cleaning his antennae.

Despite their fragile appearance, these insects are skilled hunters, capable of catching and devouring prey at least half as long and nearly as heavy as themselves. They slowly stalk crickets and moths found on the bark, constantly vibrating their antennae in a fashion similar to that in many parasitoid wasps, which may indicate the use of chemical signals in detection of their prey. I have also seen these mantids feeding at night, which further supports the possibility of using non-visual cues while hunting.

Young Sibylla are very spindly looking and are found usually on leaves and tips of thin branches.

Young Sibylla are very spindly looking and are found usually on leaves and tips of thin branches.

Although superficially similar to empusid mantids, Sibylla is more closely related to another amazing dead leaf mimic, the Ghost mantis (Phyllocrania paradoxa), which I yet need to find in Gorongosa (but I was told by a resident that he had seen one). Most of the 14 known species of the genus Sibylla are found in West and Central Africa, and the individuals from Gorongosa are the first records of this genus of insects in Mozambique.

Sibylla mantids are closely related to the otherworldly Ghost mantids (Phyllocrania paradoxa). I have not yet found one in Gorongosa, but I am pretty sure that we have them there.

Sibylla mantids are closely related to the otherworldly Ghost mantids (Phyllocrania paradoxa). I have not yet found one in Gorongosa, but I am pretty sure that we have them there.

Alas, having caught quite a few individuals of Sibylla attracted to my mercury vapor lamp in Gorongosa, I am now convinced that this pretty insect does not have the powers to foretell the future. Otherwise they would have known that if you come to my light, you never leave.

Sibylla are voracious predators of insects found on tree bark and branches.

Sibylla mantids are voracious predators of insects found on tree bark and branches.

Mozambique Diary: Blind snakes of Gorongosa

A comparison of the largest blind snake of Gorongosa, the Giant blind snake (Megatyphlops schlegelii), and the smallest one, the Peter's thread snake (Leptotyphlops scutifrons)

A comparison of the largest blind snake of Gorongosa, the Giant blind snake (Megatyphlops schlegelii), and the smallest one, the Peter’s thread snake (Leptotyphlops scutifrons)

Last night’s downpour flushed out a lot of things from under the ground, and one of them was a large blind snake, Megatyphlops schlegelii, which I found as it was swimming in a puddle in front of the Scientific Services’ trailer. Now, large is a relative term – the snake is only a little over a foot long and as thick as a finger, but for blind snakes this is huuuge. Blind snakes, families Typhlopidae and Leptotyphlopidae, comprise some of the smallest reptiles, and definitely the smallest snakes, in the world. In fact, one species, Ramphotyphlops braminus, has spread over the globe with potted plants, mistaken for a small earthworm in the soil.

Both families are considered some of the most basal lineages of snakes, which means that their morphology and behavior gives us some insight into how snakes evolved from their closest relatives, lizards (or, more specifically, clade Toxicofera, which includes monitor lizards, agamas, and a few other groups). They are all subterranean and their morphology reflects this fact in the small but massively calcified skull, hard “beak” made of thick scales that allows them to push through the soil, and incredibly smooth body that minimizes frictions as they tunnel underground. The eyes are vestigial, hidden under semi-translucent scales, and are visible only as darker, light-sensitive spots on the sides of the head. Unlike other snakes they also lack a distinct tail – the body pretty much ends in a cloaca and all that remains of the tail is a tiny, sharp spike, their only defensive weapon.

The morphology of the Giant blind snake (Megatyphlops schlegelii) reveals its perfect adaptation for subterranean life – there is no neck or distinct tail, which means that the animal can move as easily forward as backward in the underground tunnels; notice the sharp defensive spike on the end of the body.

The morphology of the Giant blind snake (Megatyphlops schlegelii) reveals its perfect adaptation for subterranean life – there is no neck or distinct tail, which means that the animal can move as easily forward as backward in the underground tunnels; notice the sharp defensive spike at the end of the body.

Needles to say, blind snakes are completely harmless. They produce no venom and may even lack teeth in either the upper or lower jaw. When caught they try to jab the attacker with the tip of the tail, which is about as effective a defense as being licked by a puppy. Still, the first Megatyphlops I saw in Gorongosa was an animal being hacked to bits by villagers afraid of its (imaginary) venom.

The body of blind snakes is glossy smooth, reducing friction when moving underground. It also makes holding them in your hand rather difficult.

The body of blind snakes is glossy smooth, reducing friction when moving underground. It also makes holding them in your hand rather difficult.

So far I have found three species of blind snakes in the park, usually while flipping rocks when looking for crickets. Interestingly, I have also seen them frequently on the surface at night, moving slowly and deliberately, as if looking for something. These snakes feed mostly on termites and ants, the nests of which are often located under rocks and logs. I imagine that it is easier for the snakes to move on the surface to the next rock, than to plow under the surface, which may explain their behavior. Some blind snakes are known to produce pheromones that mimic those of their prey, thus protecting them from attacks by soldier termites and ants. Their feeding mechanism is different from that of other snakes – more evolutionarily derived snakes swallow the prey by alternatively advancing the left and right upper jaw arches (which can move independently) over the prey. But blind snakes don’t have long, independently movable upper jaw and instead “rake” their insect prey into the mouth by stretching and pulling back their short lower (Leptotyphlopidae) or upper (Typhlopidae) jaw. Apparently, smaller species may not even swallow the prey at all, but instead suck the liquid portion of the insect’s body and discard the exoskeleton.

Peter's thread snake (Leptotyphlops scutifrons), the smallest snake in Mozambique.

Peter’s thread snake (Leptotyphlops scutifrons), the smallest snake in Mozambique.

Mozambique Diary: Devonian sashimi

A fishermen from Dingue Dingue and his catch. The first animal is the African lungfish (Protopterus annectens).

A fishermen from Dingue Dingue and his catch. The first animal is the African lungfish (Protopterus annectens).

A few years ago I wrote a book titled “Relics”, which was a way of expressing my fascination with both time travel and with all the irreplaceable forms of life that had existed long before our species sneakily appeared when Nature wasn’t paying attention. One of the organisms I really wanted to include in the book was the lungfish, a direct descendant of the organism that gave rise to all tetrapods, including you and me. Alas, I had never photographed or even seen a lungfish, and thus could not add it to the book.

Imagine my confusion, surprise, delight, disappointment, and hope when yesterday I finally ran across one of those amazing animals. I was driving around with a few friends around an area south of the Gorongosa National Park in Mozambique and at some point we stopped near a small settlement by an old oxbow lake. We saw a few fishermen and decided to see their catch. And there, among catfish and tilapias, I spotted what at first I took for a giant salamander. A second later I realized that I was looking at an African lungfish (Protopterus annectens), a spitting image of Devonian, air-breathing, land-walking animals, the first to evolve lungs, tetrapod locomotion and, as a recent study reveals, structures that eventually lead to the formation of our ears.

Alas, the fish were already dead and gutted. I was heartbroken – it felt to me as if somebody shot a triceratops for its horns or squashed a trilobite as a bug. How can you eat a relic? But my next thought was, since they are already dead, why shouldn’t I eat them? How many biologists could say that they ate a lungfish? Unfortunately, we still had many hours of driving ahead of us and I had no way keeping it cool and safe from the African sun. The only option was to eat it raw. Did I? No, I didn’t, I chickened out, but only because of the fear of contracting some dreadful disease from the water in which the carcasses were washed. But this encounter also made me hopeful that soon I will be able to catch a live one and properly document it. I have just arrived in Gorongosa, and I know that lungfish are here. The hunt commences tomorrow.

Update [4April 2014]: I got it! Read about my encounter with the first live lungfish.Lungfish2