A Gorongosa crocodile sliding into the Urema River.

Since I needed for one of my book projects a few shots of the famous Gorongosa crocodiles, which rank among the largest in Africa, I asked for help from Bob Poole, a man with considerable crocodile experience. Bob is a legendary National Geographic cameraman who shot, among other NatGeo titles, “Africa’s Lost Eden” and “War Elephants.”
We decided to set up a blind near one of the crocodiles’ basking beaches on the night before, arrive when it was still dark and sneak into the hide, and photograph the animals from there. But we both felt a bit lazy, and in the end did not leave the camp until the late morning, when the sun was already up.

Bob Poole holding all that remains of his hide, and his tripod dragged into the river by a crocodile.

When we got to our spot we found an empty beach, with not a trace of the hide. Or rather, all that we found were traces of the hide, which had been ripped off its stakes still embedded in the ground, and dragged under water by an enormous crocodile. Luckily, the beast did not take Bob’s tripod, which we found in the mud nearby.

I am not a morning person, and never in my life did I feel more grateful for that. Had we been in the hide before dawn as planned, there is no telling how our little adventure would have ended. I think I will continue sleeping in.

Tracks of the crocodile that took, and most likely ate, our hide.

Harith Farooq holding a Rock monitor (Varanus albigularis). These enormous lizards are some of the largest reptilian predators of Gorongosa, surpassed only by fully grown rock pythons and crocodiles.

Sitting on the dusty floor of a makeshift laboratory tent Harith Farooq carefully folded a piece of fine, steel mesh into a foot-long cylinder, then weaved in a stretch of a thick wire along its edge. Finally, he carefully attached a neck of an empty water bottle to one of the ends and looked at the contraption in his hands with deep concentration. “Something is still missing”, you could almost hear him think, “but what? A battery? A fork? Some gasoline, perhaps?” His gaze shifted to a stack of paper mouse traps covered with thick, sticky glue, the kind that was meant to immobilize any animal unlucky enough to step onto it. “Bingo!” – Harith picked one up and squeezed it into the tubular apparatus. “The perfect leezard trap”, he announced proudly.

Swynnerton’s amphisbaenian (Chrindia swynnertoni), a subterranean blind lizard, found only in Gorongosa and a small surrounding area.

For the last few days Harith, a Mozambican scientist from the University of Lúrio in Pemba and his colleague MO Roedel from Berlin, two herpetologists participating in a biodiversity survey of the Cheringoma Plateau in Gorongosa, had been trying to catch some of the many lizards found in the Nhagutua Gorge, the site of our first camp. Alas, the sneaky reptiles proved to be extremely difficult to catch by hand, which prompted Harith to come up with an alternative solution. As the survey progressed his traps kept growing larger and more complex, combining both natural materials (rocks, sticks, bark) and man-made objects – a plastic sheet, twine, wire and, of course, steadily increasing amounts of glue. The one thing that they all had in common was their total inability to capture even a single reptile.

Flap-necked chameleons (Chamaeleo dilepis) are common in the savanna woodlands of the Cheringoma Plateau

The strangest part was that Harith was incredibly good at catching reptiles, or any other organisms, without the need for additional accessories. I had never seen anybody catching, with their bare hands, a giant centipede, a solifugid, or a deadly spitting cobra, but Harith caught them all, while carrying a casual conversation. In the end, during the Cheringoma survey he and MO collected 47 species of lizards and snakes, effectively quadrupling the number of reptiles known from Gorongosa National Park.

Within a three week period in Gorongosa our team of biologists was able to document the presence of all nine families of lizards that occur in southern Africa. Among them were some real gems, including an entirely blind, subterranean lizard, the Swynnerton’s amphisbaenian (Chrindia swynnertoni). These tiny reptiles, known only from a handful of specimens recorded around Gorongosa, spend their entire life underground, leading a lifestyle remarkably similar to that of earthworms, and feeding on termites and ant larvae.

Thunderbolt lizard (Nucras sp.), one of the fastest animals found in Gorongosa.

On the opposite end of the lizard spectrum, two species of giant monitors (Varanus) turned out to be quite common on the Cheringoma Plateau. One day Harith walked into the camp carrying a live Rock monitor (V. albigularis) the size of a goat, which he had captured by throwing himself on top of the gargantuan animal, barely overpowering it with the help of two other people. The reptile’s snout was still covered with blood of the last victim, probably a bird or a small child, by the looks of it, and gazing into the monitor’s eyes made me realize how grateful I was that our species appeared long after the era of dinosaurs had passed. We released the beautiful creature after examining it for the presence of external parasites, which the lizard had none, proving its excellent health condition.

Plated lizard (Gherrosaurus major) was one of the most exciting finds of the survey.

Almost every day our herpetological team, which also included a Mozambican student Francisco Domingos, recorded something new and exciting. Often it was a tiny brown frog that differed from all other frogs by the presence of a slightly enlarged corner of the left supraocular cuticular fold, which was enough to make our herpetologists prance and giggle with excitement like little girls. But at other times it was a vine snake that could kill you with a half a drop of its venom, or a spiny rock lizard that defends itself by squeezing into rock crevices and inflating its body like a balloon. The survey found charismatic chameleons, among them the famed pygmy chameleon of Mt. Gorongosa, unquestionably the cutest lizard in Mozambique, and blindingly fast lacertid lizards with flame orange tails, which looked like tiny thunderbolts zipping across the ground.

The survey officially ended yesterday, and Harith is on the way back to Pemba. Data collected by him and the rest of the herpetological team will be added to the ever growing Gorongosa biodiversity database, a powerful tool that helps manage the restoration efforts in the park. I was sorry to see the members of the team depart, but having witnessed Harith handle cobras and puff adders as if they were harmless puppies I was relieved to see him leave the park, still alive and well. All things considered, a gash in his finger, courtesy of a pouched rat, followed by a nip from a giant scorpion hardly count as injuries.

The male Gorongosa girdled lizard (Cordylus mossambicus) looks like an alligator wearing an orange T-shirt. These spectacular reptiles are found only in a small area around Gorongosa and the neighboring Chimanimani Mountains of Zimbabwe, and are threatened by habitat loss and overcollecting for pet trade.

A strange chimera, the feather-legged centipede (Alipes sp.)

A couple of weeks ago I was ripping slabs of bark off an old fallen log, an activity that to me ranks among the most pleasurable things one can do, right up there with unwrapping Christmas presents. There is always a chance of finding something incredible – a beautiful cerambycid beetle, a colony of Pyramica, a ricinuleid. But then I pulled off a big chunk of bark and caught a glimpse of an animal that made me think that I am having a stroke. For a split of a second I saw what clearly appeared to be a large centipede, nothing unusual about it, only this one had two long feathers attached to the back of its body. Before I could get a really good look, it jumped off the log and disappeared in a tangle of branches on the forest floor. “I must be really dehydrated” was the only explanation I could come up with, and I made an active effort to forget about the whole thing.

But the strange chimera turned out to be very real. Last night, while rummaging around the camp at night, I found another one. The animal is indeed a centipede, a member of the mysterious genus Alipes (“feather leg”), closely related to scolopendras, and found only in parts of eastern Africa. Its last pair of legs is modified into large, feather-like paddles, the function of which is unclear. According to some sources the “feathers” can vibrate to produce a rustling sound, but I find it unlikely as they are quite soft and very flexible. This animal is also unusual among centipedes in possessing distinct longitudinal ridges on its tergites (most species have the dorsum smooth and shiny). Otherwise it behaves like a typical scolopendra, always trying to bite you and ripping to shreds any animal that it can sink its fangs (forcipules) into. And if anybody knows more about this amazing animal I would love to hear it.

A closeup of the “feathers” of Alipes. Their function in this centipede remains a mystery.

The best time to see Atlantic horseshoe crabs (Limulus polyphemus) is on the nights of the full and new moon in May and June.

I am still in Mozambique, and will be here for a few more weeks, but I simply must take a quick break from describing African nature to highlight a spectacular phenomenon that is taking place right now along the eastern coast of North America – the mass spawning of the Atlantic horseshoe crabs (Limulus polyphemus). Watching these magnificent animals is to me one of the most beautiful natural events that one can witness, and I encourage everybody living on the East Coast to take a trip to the beach this and next month (this year the best time to see them are nights of May 24th, and June 9th and 23rd.) What follows is a short excerpt from my book “Relics” (Chicago University Press 2011), describing my experience of watching horseshoe crabs on the beaches of the Delaware Bay.

“As hundreds of biting flies did their best to drain us of every drop of blood, my friend and fellow photographer Joe Warfel and I stood on the beach, waiting for the spectacle to begin. The sun grew dim, and the high tide was nearing its peak. There were a few people on the beach when we first arrived, but by now they had all disappeared, and we were the only witnesses to what was about to unfold. I started to tell Joe how strange it was that nobody else stayed to watch, but swallowed a fly and decided to quietly enjoy the rest of the evening. First came the big females. Nearly all had males in tow. In the dimming light we could see spiky tails of hundreds more as they tumbled in the waves, trying to get to the dry land. By the time the sun fully set, the beach was covered with hundreds of glistening, enormous animals. Females dug in the sand, making holes to deposit their eggs, nearly 4,000 in a single nest, while the males fought for the privilege of fathering the embryos. Fertilization in horseshoe crabs is external, and often multiple males share the fatherhood of a single clutch. Equipped with a pair of big, compound eyes (plus eight smaller ones), capable of seeing the ultraviolet range of the light spectrum, male horseshoe crabs are very good at locating females even in the melee of waves, sand, and hundreds of other males.

Delaware Bay is the best place in the world to see these magnificent animals. On a good night one could easily see 100,000 horseshoe crabs.

Horseshoe crabs have been around longer than most groups of organisms that surround us now. A recent discovery in the fossil deposits of Manitoba, an interesting little creature named Lunataspis aurora, proves that horseshoe crabs quite similar to modern forms were already present in the Ordovician, 445 million years ago. By the time the first dinosaurs started terrorizing the land in the Triassic (about 245 million years ago), horseshoe crabs were already relics of a long-gone era. And yet they persisted. Dinosaurs came and went, the Earth changed its polarity and climate many times over, but horseshoe crabs slowly plowed forward. Yet during this time they changed surprisingly little. Species from the Jurassic were so similar to modern forms that I doubt I would notice anything unusual if one crawled in front of me on the beach in Delaware. Somehow horseshoe crabs had stumbled upon a lifestyle and morphology so successful that they were able to weather changes to our planet that wiped out thousands of seemingly more imposing lineages (dinosaurs and trilobites immediately come to mind.) But despite claims to the contrary by creationists and other lunatics, they kept evolving. Modern horseshoe crabs, limited to three species in Southeast Asia and one in eastern North America, differ in many details from their fossil relatives. We know, for example, that many, if not most of fossil horseshoe crabs lived in freshwater, often in shallow swamps overgrown with dense vegetation, and some might have even been almost entirely terrestrial. Currently only the mangrove horseshoe crab Carcinoscorpius rotundicauda from the Malayan Peninsula routinely enters rivers, and is the only species to lay eggs in fresh or brackish water.

Even Sir David Attenborough, a man who probably witnessed more natural spectacles than any other human being, is fascinated by the spawning of horseshoe crabs. Here he demonstrates the improper way of holding a horseshoe crab (never hold them by their telson) while on the beach in Delaware during the filming of the BBC series “Life in the Undergrowth”.

The following morning Joe and I found the beach covered with horseshoe crab eggs. Well-rested and ready to start a bright new day the flesh-piercing flies attacked us with a renewed enthusiasm. Flailing our arms and swatting dozens at a time we went about flipping crabs stuck on their backs in the sand, and started to look for particularly big clutches of eggs. Although females burry the eggs in the sand, the returning tide washes out many of them. Freshly laid eggs are small, not larger then half a grain of rice. Surprisingly, the eggs grow as they develop, eventually becoming more than twice as large. This, of course, is impossible. The “growth” is an illusion, the result of the production of an external, thin membrane by the developing embryo. A fully developed egg, which at this stage has spent two weeks in the sand, resembles a tiny glass aquarium, with a petite horseshoe crab twirling inside, impatient to break the walls of its miniature prison. Once free, the larva (or at least the lucky ones) catches a wave back into the ocean and will spend about a week floating freely, before settling on the bottom of the shallow shore waters to begin life akin to that of its parents.[…]“

Tiny horseshoe crab larvae, known as the trilobite larvae, twirling in their aquarium-like egg shells. Soon they will break free to begin a short pelagic period, after which they settle on the bottom of the ocean to begin a lifestyle similar to that of their parents.

Just like their distant relatives, scorpions, horseshoe crabs display green fluorescence under the ultraviolet light.

Atlantic horseshoe crabs on the Prime Hook Beach near Milford, Delaware.