by Simon Barnes
There is not much food here, which is why anglerfish have resorted to the extreme tactic of the glowing lure. You won’t find prey by looking for it; there’s not enough of it about. You have to bring it in. This is not the teeming life of the coral reef: these are the wide – and high – open spaces of the ocean where a fish can be alone in the bleak three-dimensional wastes. And this poses yet another problem. It’s hard enough to find food: how the hell are you supposed to find a mate and have sex and make more anglerfish?
The answer is as mysterious as the lure. When anglerfish were first being recovered from the deep ocean, scientists were puzzled. Why were the specimens they caught always females? And why did these females always have several parasites attached to their bodies? Where were the males? How did they have sex? The answer to all these questions was already before them. That’s no parasite: that’s my husband. Or one of them. The males are born stunted and minute. In some species the male’s alimentary canal is so rudimentary that he can’t even eat, he must find a female or die. These tiny males have one – make that two – talents. The first of these is the ability to find females in the trackless wastes of blackness. They have a high-grade olfactory system that allows them to detect the pheromones put out by females, and to do so over immense distances. They lock onto a distant female and swim towards her as if their lives depended on it, and for the very best of reasons. Once a male has found a female he bites into her skin and releases an enzyme. This digests both the skin of his own mouth and the outside of her body, eventually fusing the two together. The male locks into the female’s circulatory system and obtains nutrients that way. After that, he performs his second best trick when required and produces sperm to fertilise the female’s eggs.
Queerer than we can imagine. There is not a single place where it’s impossible to demonstrate that eternal fact of life: not a single environment, not a single ecosystem, not a single phylum, not a single class, not a single order, not a single family, not a single genus, not a single species. If you could dive down to the places where you leave light behind you would find that, weirdly, almost horribly, you don’t leave life behind. It’s there in all its glorious queerness.
The wasp and the devil’s chaplain
Wasps are the express route to the problem of evil. It starts with the question of why God created wasps to spoil our picnics and moves on at breakneck pace to forms of behaviour that are still stranger and more sinister. So much so that Darwin wrote: “I cannot see as plain as others do, and I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars…”
And that’s exactly what they do. Ichneumons are wasps that possess what looks like an extra-long sting. It’s in fact an extra-long ovipositor or egg-laying device. The sting evolved from the ovipositor,I which is why only females can sting you. But the ichneumons have no ambition to cause humans pain, nor would it be any use to them if they did. They use the ovipositor to lay an egg inside a living creature, generally a caterpillar or a pupa. The ichneumon larva hatches out inside the creature and proceeds to eat its host from the inside while keeping it alive, which means its food will stay fresh. Stephen Jay Gould compared the process with the hanging, drawing and quartering of traitors: “As the king’s executioners drew out and burned his client’s entrails, so does the larva continue to eat fat bodies and digestive organs first, keeping the [victim] alive by preserving intact the essential heart and nervous system.”
Some of the larger species of ichneumon are so adept at the task that they can lay an egg into a grub through a thick layer of wood: seeking out larvae by listening for them from the outside and then injecting the egg straight through the larva’s protection system into the larva itself. There is an impressive ingenuity in all this, but it’s not the sort to appeal to those who look for hummingbirds while ignoring the Loa loa worm. There are about 60,000 species of ichneumons, so this is a way of life that works very well indeed. Jennifer Owen spent 30 years documenting the insects in her garden, no enormous area, in suburban Leicester. In the course of her studies she identified 1,602 species of insect which included a staggering 529 species of ichneumon, of which 15 were new to Britain and four new to science. In further studies she added 74 more ichneumon species.II The ichneumon model is no one-off example of super-evil: it’s a raging success, and therefore commonplace.
Wasps can be defined as all members of the order Hymenoptera and the suborder Apocrita that are neither bees nor ants. These include many species of hunting wasp, which is a descriptive rather than a taxonomic term, covering a large number of wasps that live in a similar way without necessarily being closely related. Many of these provide touching examples of maternal care. When an egg has been laid, the female provides her progeny with a larder. She collects food, mostly other arthropods. But she doesn’t kill them. If she did that they’d go bad and the emerging larva would have nothing worth eating. Instead she paralyses them, and carries the inert but still living creatures, often spiders, back to the waiting egg. Gerald Durrell wrote: “If the spiders are small there may by anything up to seven or eight in a cell. Having satisfied herself that the food supply is adequate for her youngsters, the wasp then seals up the cells and flies off. Inside the grisly nursery the spiders lie in an unmoving row, in some cases for as much as seven weeks. To all intents and purposes the spiders are dead… thus they wait, so to speak, in cold storage until the eggs hatch out and the tiny grubs of the hunting wasps start browsing on their paralysed bodies.”
In one of his stand-up routines, Steve Martin makes an appalling sexist joke and then tops with the irrefragable statement: “Comedy is not pretty.” Nor is life. It’s either funny or it’s not; it’s either living and procreating or it’s dead, extinct and gone.
Darwin wrote again: “What a book a devil’s chaplain might write on the clumsy, wasteful, blundering, low and horribly cruel works of nature!” A devil’s chaplain has untold amounts of material to work on, but it would not confound any thoughtfully religious observer of nature (like, say, Simon Conway Morris), or for that matter, any serious theologian.III The existence of ichneumon wasps and hunting wasps is not proof that God doesn’t exist, any more than these species’ behaviour is proof that there is no such thing as, or no need for, morality. All these creatures prove is that there are no easy moral lessons to be learned from the non-human world: or to turn it the other way round, the ten million or so species on earth do not exist in order to teach humans how to operate human society.
And besides, I have a fond and treasured memory of hunting wasps. I was waiting at the entrance of the South Luangwa National Park while the formalities of paperwork were going on, when my older boy, then aged ten, pointed out with a sudden whoop of delight: “Look! Right there! Just like we saw on David Attenborough!” And there indeed were hunting wasps excavating the needle-narrow holes in which their eggs would be laid and the “grisly nursery” established. I would never have noticed them without his keen eyes, his keen mind. In rich content we carried on to share more adventures in the bush.
* * *
I. In other words the two are homologous, like lungs and swim bladders.
II. A story told in the indispensable Bugs Britannica by Peter Marren and Richard Mabey.
III. A species conspicuously absent in Richard Dawkins’s fundamentalist tract The God Delusion.
The sinking fish
You wouldn’t think a fish that sinks was the most efficient piece of design, but it works for the most feared predator on the planet. Sharks, like your author, are negatively buoyant. They operate from a design that is strikingly dissimilar to the ray-finned fish we have just met. The skeleton is different, as we shall see in the next chapter but one; in fact, the entire body plan is different. The swim bladder is central to the ray-fi
nned fishes’ way of life, but sharks don’t have them. That’s one of the reasons why my Balinese shock-shark looked so radically different from all the other fish around: it was moving forward with such great purpose. The reason sharks don’t hang about in the ocean is because they can’t.
Sharks need to pass plenty of water over their gill slits in order to breathe, and most species can only do this by moving. A few species, the nurse shark, for example, can rest up on the sea bottom and push water over their gill slits, but for most sharks, life is about keeping on the move: moving with crisp purpose. Sharks can swim forward while sleeping: they have to. Awake or asleep, every one of them looks like a shark on a mission, which is perhaps one of the reasons why they always look alarming. Every time you see a shark it looks as if it’s after something, probably you – but usually all it’s trying to do is breathe. Woody Allen’s famous line in the film Annie Hall is based on proper natural history: “A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. What we have on our hands is a dead shark.”
In this book I have constantly touched on humankind’s innate inability to grasp the true nature of the diversity of the wild world. It’s been suggested that we don’t have the mental equipment to do so: that when we reach a certain number of different sorts of animals, our brains come up with an atavistic kind of “memory-full” response.I We can appreciate the idea that there may be more shark species than the great white, but very few of us could get into double figures. And yet there are more than 470 species, ranging in size from the dwarf lantern shark at 17 cm, 6.7 inches, to the whale shark at 12 m, nearly 40 feet. We can accept that there may be many more kinds of wasps than we know about, but we can easily write that off as mildly interesting, a matter for specialists, not really our concern. Sharks, on the other hand, fascinate humans as much as any other group of animals – and yet we still can’t begin to cope with their diversity. Sharks, like practically every group on this planet, are not only more diverse than we suppose, they’re also more diverse than we can suppose.
Of all the shark species, only four have been known to make unprovoked attacks on humans: the great white, tiger, bull and oceanic whitetip. Between 2001 and 2006 there was an average of 4.3 unprovoked attacks each year across the entire world. Knowledge of that stat won’t, of course, stop me repeating my penguin impression if I have another encounter, nor will it affect the deep, almost reverent feelings of terror that sharks inspire in us humans. It seems we have a need for these monsters. And even if their human strike rate is low, it has to be admitted that their equipment for attack is singularly impressive. Their teeth operate on a sort of conveyer belt, constantly renewed. It has been estimated that some sharks get through as many as 30,000 teeth in a lifetime, sometimes replacing a tooth in just eight days.
The pupils in their eyes expand and contract like those of mammals, and unlike those of the ray-finned fishes. Their sense of smell operates at long range and the distance between their nostrils gives them the ability to locate the direction of the scent. It has been suggested that the extreme adaptation of the hammerhead is designed to maximise that distance and give the most precise cross-bearing possible. All sharks hear well. They can also detect the electromagnetic fields that all living things produce; the sharks’ sense of electroreception is the best in the Animal Kingdom. Sharks are considered to be intelligent and curious, and there are anecdotal reports of them indulging in play.
Not all sharks are apex predators like the great white, tiger, blue, mako and hammerhead. The dogfishII – these days more often referred to as the cat shark – is a charming little shark you sometimes find in rock pools on British beaches. The cookiecutter shark is a small shark with disproportionately enormous teeth. It has never been observed feeding, but the surmise is that it launches itself at much larger fish, seizes hold, makes a tight seal with its unusually thick lips, and then twists away violently to make off at high speed with a single mouthful of fish – leaving behind an almost perfectly circular scar, as if someone had, indeed, been using a baker’s tool.
One of the weirdest sights I have ever seen in British waters – or any waters for that matter – was a group of five basking sharks, all between 10 and 12 feet, 3 and 4 m. You could estimate the size by taking the distance between the dorsal fin and tail-tip and doubling it. These are filter-feeders, sharks that cruise at their ease through the oceans feeding on plankton with a gaping ever-ravenous mouth. The whale shark is another filter-feeding shark, and it is bigger than all other species formerly classed as fish.
But let’s get back to the great white shark. And I wouldn’t like you to get the idea that it’s harmless. It is a superbly effective ambush predator, up to 6 m, 20 feet, long and preying on tuna, other shark species, dolphins, porpoises, small whales and seals. The great whites are not necessarily out to get you, but I’d hate you to think that they weren’t fearsome. The famous book and film exaggerated their taste for human prey, but they’re still some of the finest, most brilliant and most glorious monsters on earth.
* * *
I. See Naming Nature, by Carol Kaesuck Yoon, subtitled The Clash Between Instinct and Science. She suggests that humans can’t cope with more than 600 groups of animals. She got two scientists, one her husband, to list all the genera they knew, expecting them to blow this theory out of the water. Both got as far as the high 500s and got stuck – unable to recall even animals that were familiar parts of their studies.
II. They used to be served up in fish and chip shops under the euphemistic name of rock salmon.
The best butter
A shard of flying light, yellow as butter, bright as if freshly churned, greeting the spring, the first to emerge that year, floaty and fluttery and as fragile as a nice day in England. A butterfly then, a brimstone, the insect that put the butter in butterfly, whose creamy-yellow colouring gave the name to thousands of species across the world. “It was the best butter,” as the March Hare said meekly to the Mad Hatter, having used it to fix the Hatter’s watch.I
So now let’s switch to a summer evening, a family gathering round the table, much laughter in the warm air. It had been dark for an hour or two now, and what’s that fluttering round the candles seeking the flame with such dreadful certainty? I gathered the moth in my cupped hands, a hawk moth, so large it was almost an honorary bird, a poplar hawk moth, I think it was, but I didn’t stop to examine it for long, and as it tickled my palms in all its eternal vulnerability, I took it some distance from the light and lobbed it skywards, willing it to find a better target for its passion.
Butterflies and moths. Lepidoptera, which means scaly wings. How many species? One estimate gives me an alarmingly precise 172,250 species, There are rough and ready differences between butterflies and moths, but it’s not a true taxonomic division: better accept that there are no moths and no butterflies, much as there are no fish. Plenty of moths make their living in sunlight: the six-spot burnet is rather a favourite of mine, and the silver Y moth is the butterfly you can’t identify as it sups nectar from the flowers. I have a neighbour, David Wilson, who did the illustrations for Colour Identification Guide to Moths of the British Isles, and he did a rare and splendid thing for me. I had spent a fine evening with him, in which we raided his moth traps, drank a beer, raided and drank again and so forth: an excellent way of doing natural history. I am no great shakes at moth identification but it is always good to spend time with people prepared to explain the passions of their lives. And I told him I had always wanted to see a hummingbird hawk moth.
A few weeks later he rang me up to say that one was currently visiting his garden if I could get along quickly. Alas, I was covering a cricket match many miles away and couldn’t make it. After a few more weeks he invited me round again. He had caught the moth, and when it had laid eggs, he had released it. He had hatched the eggs out and fed the caterpillars and he now had a fully emerged moth. This time I was able to get round right away. At his invitation, I release
d the moth, which crawled onto my finger and savoured the air of the Suffolk garden before committing itself. We joked that it would probably die on the spot or get eaten by a hungry bird straight away, but not a bit of it. After a while it took to the air and flew straight to the adjacent buddleia bush and started to take nectar: hanging in the air in exactly the manner of a hummingbird. Every year many people ring conservation organisations to report that they have a hummingbird in the garden, but it’s a British moth pulling off exactly the same trick. It’s yet another example of evolutionary convergence.
If the ichneumons are the insects for the devil’s chaplain, then butterflies redress the balance for the opposition. To see a butterfly is to be convinced that the world exists for nothing but peace, love and beauty. I recall a butterfly in the Luangwa Valley, right at the end of the dry season in the ferocious murdering heat, as lovely a thing as I have seen: black, painted in iridescent green streaks, with two long and elaborate tail streamers. This, I eventually worked out, was a cream-striped swordtail, each wing the size of my palm. Back in England there is a butterfly nearly as extravagant, one you can find in season in the more obscure parts of the Norfolk Broads. I found swallowtail for the first time at Hickling: improbably large and improbably bright and yellow-patterned, moving with a sense of urgency over the tops of the reedbeds.
Butterflies are unambiguously lovely: moths in their muted way not much less so, even though they are associated with such sinister things as night and darkness. It is not necessary to say you find butterflies attractive: it’s an instinctive part of human nature. Yet we find caterpillars mildly repulsive. I remember a cartoon of two caterpillars looking at a butterfly: “You’ll never get me up in one of those.” Butterflies, like many insects, compartmentalise their lives: as if we humans spent the first 65 years of our lives doing nothing but eat, and then gave up solid food and, getting a bus pass, spent our remaining few months or years as full-time sex maniacs.