Ten Million Aliens

by Simon Barnes

  So here’s yet another of those fuck-me moments that a walk across the African savannah will hand you with such reckless generosity. It concerns something much smaller than an elephant, but it produces the same head-wagging sense of wonder and privilege: the same not-quite-disbelieving revelation of the liveliness of life. Stoop for a moment and pick up a shell. The gastropod body has long left, but what you hold in your hand is something you will always remember.

  It’s the shell of one of the great African land snails: a group of species that to most of us look impossibly huge. To give the dimensions doesn’t really do the experience justice: say, 8 inches or 20 cm long, and up to 3 inches or 8 cm high. There have been some even bigger individuals: a length of 30 cm or a foot, and a diameter of 6 inches or 15 cm. But it’s holding it in your hand that matters: the feeling that this can’t be right, that snails simply aren’t that big. Imagine a song thrush trying to hammer this baby against a stone: the song thrush could practically creep inside the (right-handed) spiral of the shell. It’s an experience that says something about the brilliance, and the limits of the gastropod body plan. Oh brave old world that has such gastropods in it!

  The land-dwelling shell-wearing gastropods are familiar to all of us: we give the whole lot of them the name of snails and believe that that is the end of the matter. But an encounter with one of these African monsters destroys this complacency. We live in a world of wonders whether we like it or not: and no matter how we view it there are very many more kinds of everything than our minds can cope with.

  Stephen Jay Gould, the great writer on evolution and related topics mentioned elsewhere in these pages, was especially devoted to snails. Like Darwin with his barnacles and his earthworms, Gould believed that big ideas come from minute studies. He had a special fascination for the West Indian snails of the genus Cerion, the molluscs the Jamaican shell expert Honeychile Rider forgot. Here’s Gould:

  “Cerion is the land snail of maximal diversity in form throughout the entire world. There are 600 described species of this single genus. In fact, they are not really species, they all interbreed, but the names exist to express a real phenomenon which is the incredible morphological diversity. Some are shaped like golf balls, some are shaped like pencilsI… Now my main subject is the evolution of form, and the problem of how it is that you can get this diversity amid so little genetic difference, so far as you can tell, is a very interesting one. And if we could solve this we would learn something general about the evolution of form.”

  The key, then, to one of the most important questions about the development of life on earth is to be found in these snails. These snails hold the meaning of life… in common with every other species I have mentioned in this book, in common with all life on earth.

  * * *

  I. Gould suggested that if only Columbus had picked up a Cerion shell and kept it safe, we would know exactly where he first landed in the (brave) new world.

  Wild thing

  An area of wet scrub in Norfolk: reeds, dense vegetation, behind it some taller shrubs. And from the scrub a song. Was it reed warbler or sedge warbler? I paused to listen, for this was a decent singer, and either species is worth a listen. It was mid-June, late in the year for such a tremendous burst of sound. The conundrum of the singer’s identity began to intrigue me: the pair should be pretty straightforward to tell apart, but this bird seemed to be singing like both of them. And there was more to the song than there should be. It was not as rhythmic as the reed warbler ought to be, and rather greater in range and imagination than the sedge usually is. And were there other birds in there with him? And at least one, no, two singers I didn’t recognise at all. Or did I? There was something familiar going on, but increasingly the bird – surely there was only a single singer – had me baffled.

  It was my companion, Carl Chapman, who runs Wildlife Tours and Education from Norfolk, who cracked it. Marsh warbler. A bird that comes to England to breed in tiny numbers – 20 to 40 pairs a year has been suggested – and to do a spot of singing. It’s a classic LBJ, Little Brown Job, member of the hijoputido group. But when it sings it becomes one of the most glorious, extravagant and over-the-top birds on the planet. It can sing for an hour or more without a break, and in that time create a song of such wit and invention that it leaves you staggered. It’s most famous for incorporating into its repertoires the songs of other species, and twisting and turning them to its own purpose. One famous piece of research on a small population counted a total of 212 different species imitated, each male having an average repertoire of 76. You need quite an ear to pick them all out, for they are jumbled together to conform to the bird’s individual notions of music. The whole business is complicated by the fact that the bird spends its winters in Africa and picks up at least half of its repertoire down there. The 12 European birds that it is most commonly heard to imitate are blackbird, house sparrow, tree sparrow, whitethroat, swallow, blue tit, linnet, skylark, starling,I stonechat, great tit and magpie. But these can be hard to pick out among all the Africans, many birds I am deeply familiar with. One observer heard a chaffinch’s characteristic spinkII call melding into the call of a puffback from Africa, and a blackbird song woven into that of white helmet-shrike, another African.

  The marsh warbler is one of the great singers of the world. The entire membership of the group of warblers are pretty much LBJs, sometimes with thrilling bits of olive-green thrown in. They are inconspicuous and to a considerable extent indistinguishable. They sing their colours instead: they sing their identity as a species, and the more complex singers among them sing their own individuality as well. Some birds like the chaffinch – not a warbler – sing the same phrase endlessly and seem never to tire of it; others like the marsh warbler, the nightingale, the skylark and the song thrush are inventive and creative and individual. So much so that they seem to sing for something beyond the hardcore Darwinian reasons of procreation. Biologically, yes, a bird sings to establish and defend a territory, to find and protect a mate and then a brood. But I suspect that they sing also because it is in their nature to sing. They sing because they must: because the music in them needs to escape. Marsh warblers love to sing and three or four males will on occasions form a group and sing together, softly and more economically than when they are protecting a territory. It seems they are singing for the pleasure of it, for there is no apparent biological function to these glee parties. They just enjoy singing, singing together, sharing material and making music. This is nothing less than a jam session: and I hope you like jammin’ too. The best singers among a population of songbirds, the most inventive of the repertoire singers, tend to get the best territories and the best mates: but surely when a bird sings, it sings the song of itself, rather than merely sending out a biological signal. Birdsong, like the peacock’s tail, is more beautiful than it needs to be in terms of mere biological function. The great avian singers are surely creative artists.

  Most birdsong comes from the passerines, and of these, most come from the oscines, a group that is often loosely referred to as songbirds, for all that birds which are not songbirds also sing. And this bounty of song has provided the soundtrack of planet earth. I have suggested elsewhereIII that birds gave us more than half our music. Rhythm is our birthright as mammals: we humans spend the first nine months of our existence in thrall to the 4/4 heartbeat rhythm of our mothers. But for melody, we turned to the birds, and the first human instruments were bird flutes, frequently made from the hollow bones of birds to add to their magic.

  There is a particular intimacy about the relationship between birds and humans. Birds are daytime flaunters while mammals are so frequently nocturnal skulkers. Most mammals operate by smell, which is a sense we are incapable of understanding as a dog does. But birds are mostly creatures of lightIV and colour and sound, and we have lived alongside them and we have looked on them as creatures that enhance our lives from the dawn of human existence on the African savannahs – where our ancestors doubtless imitated the songs
of the birds and joined them together and improvised on them and jammed with them as a marsh warbler does. We humans are mammals, but in many ways we have a closer relationship with a quite different order in the same phylum. The song that shares its title and its opening line with this chapter headingV continues: “You make my heart sing!” Birds taught humans to sing, to express our joys in song. Birds provide many ecoservices for humankind, but perhaps the most important of them all is right here. They sing: they make our hearts sing.

  * * *

  I. Which is itself a famous mimic.

  II. The call, usually transliterated as spink, can also be written as finch. As such it gives the name to the entire family to which it belongs.

  III. Birdwatching with Your Eyes Closed, published by Short Books, 2010.

  IV. “Ineluctable modality of the visible”: start of the third chapter of Ulysses.

  V. “Wild Thing”, written by Chip Taylor in 1965, was covered by The Troggs the following year. It was performed, perhaps definitively, at Monterrey Pop Festival in 1967 by Jimi Hendrix.

  On our last legs

  Here, then, is the last phylum to be introduced in this book. I’ve devoted an awful lot of the words in the vertebrate cycle of this book to us fellow mammals, but that’s because I’m a mammalian chauvinist pig. I must devote every bit of the rest of the invertebrate cycle to the arthropods, because I have no option. Get ready, then, for legs. Lots and lots of legs. Arthropods go in for legs in sometimes reckless numbers, constantly reminding us how little we have in common with them. Arthropods include crustaceans, that is to say lobsters and crabs and the woodlice in your back garden. They also include a weird little group called sea spiders. They include the arachnids, which are far more than just spiders. Then there are the curious horseshoe crabs. And – oh yes – there are insects. Endless, endless, endless forms of insects, some of them most beautiful, others rather less so, at least to my eyes, and no doubt to many others’, though lovely enough to their conspecifics.

  Arthropods are fantastically variable. Never mind this being the Age of Mammals, or the Age of Humans: as said before, this is the Age of Arthropods, and it has been so from one geological era to the next. The earliest arthropod fossils are – though this is naturally disputed – pre-Cambrian, dating back to 555 millions years ago. Arthropods surpass every other phylum in the Animal Kingdom as greatest does least. Of all the animal species described, 80 per cent are arthropods. They comprise more than 2,500 families, and about 1.2 million species. Those, at least, are the ones already known: you can make your own estimate about how many remain to be described, bearing in mind that a top-quality field naturalist can find a new species with every saunter in the rainforest, on more or less every tree in the rainforest. Some go as high as ten million; others will bid still higher. It has been said that we don’t even know what order of magnitiudeI to think in. That’s the concept that really hits home, I think; the concept that reveals so many of the obscure truths about life on earth: that there are so many different kinds of animals that we don’t know whether to think in thousands or millions or billions.

  What is it that unites the giant crabs, the horrible hairy spiders of living nightmare, the city-building termites, the incomparable butterflies and the plaguey flies? First it’s the tough outside of them. All arthropods wear a cuticle made of chitin and protein. This makes up an exoskeleton: the arthropod’s equivalent of Le Corbusier’s machine for living in. The second thing is the segmented body. The number of segments varies, but the idea of dividing the body up into individual chunks is common to all arthropods. And after that it’s the jointed appendages: the sticky-out things that are also armoured in chitin, but can move and flex because of the ingenious way they are hinged. Appendages can include antennae, mouthparts, sexual bits and – yes, that’s right, legs.

  Let me tell you about an experience – an epiphany – that involved 376 legs, 378 if you include my own, even if I was pretty legless at the heart of the story. Of all my African boasts – and as you know to your cost, they are many – this is the one that, I think, shows the greatest courage: the sort of courage you can always summon up when you have absolutely no choice in the matter. You give it the name “courage” just to encourage yourself. I was staying with friends in Zambia and it had been a good day. I had ridden a horse across their ranch, which was enormous and full of antelopes and mature trees. The meal at the house had been good, the after-meal was long and whiskified and full of talk and laughter and good tales. I was staying about a mile down the road in one of their guest huts; I was driven there, it not being safe to walk about. I said my goodnight, opened the door and turned on the light.

  Now this was a well set-up hut, with insect gauze over the windows and so forth. No need, then, for a mosquito net. And on the walls and ceiling there were a few spiders. I shall be frank: I don’t care for spiders. I don’t run screaming from them, but I’m not happy about them. I can pick up a moth in my cupped hands and feel its tickling struggles as I transport it to safety: I couldn’t think of attempting any such manoeuvre with a spider. And these were not the modest little things you get in a house or a garden in England. They were serious. They were from the group of wolf spiders: not web-builders but spiders that lie in wait and jump on stuff. They ranged in size from a 3-inch to a 6-inch leg-span, 8–15 cm, with the emphasis on the latter. Not that I put a ruler on them. But I did go as far as to lie on the bed and count them: eight legs to each one (even if quite a lot of the legs seemed to be worth double), and that made, as I say, 376 legs in all. Which divided neatly enough into 47 spiders. I think this counted as a fuck-me moment. Perhaps also a fuck-off moment. Certainly it was some kind of epiphany. So I had a choice. Or to put it another way, no choice. I could in theory face possible injury and death by walking back across the bush, and certain ignominy if I survived, or I could deal with my own not-quite-gibbering terror.

  I didn’t need a drink. There was plenty of whisky in the bloodstream already. But just for the look of the thing, I poured myself a slug from the duty-free, mixed it with a dash of water and sat there drinking and staring and counting and meditating on the phenomenon of legs. And my conclusion was that arthropods are the world masters of legs: that legs are the way in which they deal with the problems of the world: legs in multiplicity. Two or four is no good at all for them. An insect insists on six, a spider on eight, 750 have been counted on one of the giant millipede species.

  I finished my tautologous whisky. Extinguished the light. That was the brave bit. Shamelessly pulled the sheet over my head: I knew they wouldn’t actually drop on my face like little, hairy, wriggling, giggling and jiggling bombs in the night, but I didn’t want to give them the option. And I slept the sleep of the just and the courageous and the pissed until morning. A sore head, but greatly enriched all the same. It’s not every day that you get a chance to contemplate legs in such profusion: not every day that the wild world forces you to spend so much time thinking about the world of invertebrates. And their teeming, scuttling, multiform, multipurpose brilliance.II

  * * *

  I. A different order of magnitude comes with each additional nought.

  II. There is a species of wolf spider that lives in the volcanic tubes of Hawaii, where it is in some danger because the tubes are drying out. Water extraction for farming is the problem. They come from a group known as big-eyed wolf spiders, for the obvious reason, but these cave spiders, though clearly related, are in fact blind. So gloriously, they are known as the no-eyed big-eyed wolf spider.

  Blood-chilling

  There was a moment when I stood precisely on the line that divides mammals from reptiles. Us warm-blooders from them cold-blooders. The hot-blood–cold-blood cusp. It certainly chilled my blood. I was on the banks of the Grameti River in Tanzania, one of the rivers that cross the Serengeti. It was an idyllic scene: like one of those Constable landscapes in which nothing can ever go wrong. A line of trees followed the banks of the river, the canopy closing ove
r the middle of the narrow stream so that the river ran through a green tent. It was pretty narrow at this point, no more than 20 yards. From the canopy, two of the sweetest voices in Africa, soft and subtle: the orange-breasted bush-shrike, singing charming improvisations around the first few notes of Beethoven’s Fifth, and the black-naped oriole with his liquid whistle. It was a landscape, a soundscape of perfect peace, annihilating all that’s made to a green thought in a green shade.

  I left the vehicle and walked – almost – to the water’s edge. It looked the perfect place to take off your clothes and walk into the water in the company of a couple of girls from a Gauguin painting. Until you looked at the water. Not logs, no. Crocs. Enormous crocodiles. Three or four of them, half a dozen, no, more, look upstream, look downstream. A lot of very big crocs in a very small river. Now if you are used to looking at wildlife you start to understand something about what’s fitting and what’s not, and this was not fitting. This gathering of enormous crocodiles was too much for a river so small and so charming. There was not enough food here for a dozen or more full-sized 16-foot, 5-metre, crocodiles. There had to be something else. And it was me.

  Or us. As I stood by the river, I could see very clearly that the crocs were looking at me. Looking at me with great interest. They didn’t hunt for their food in the water: what’s the odd fish to a beast that size? They expected food to come to them from the land, and they expected its blood to be warm.

  I had spent the last few days with wildebeest, celebrating the extraordinary business of their migration. And then I travelled onwards, getting effectively two weeks ahead of the migration front, and that brought me as far as the Grameti River. In a fortnight’s time, then, the wildebeest would be crossing. There they would meet the crocodiles, the crocodiles who hadn’t eaten since the last time the wildebeest came through, the crocodiles who hadn’t eaten for a year. And they were very bloody hungry. A year’s wait between meals, but then it was bonanza time, a fortnight or so with an endless conveyer belt of food. Soon the buffet would arrive, each dish calling to another with the great frog-bleat of the wildebeest: Newp! Newp! No fish for these crocs. Mammals. Us lot. The crocs possess a body that can operate on slo-mo, sitting out days and days of quiet and starvation, waiting, always waiting, waiting without any concept of patience, still less of impatience. Boredom? What’s that to a reptile? What’s a year between meals, what’s 50 weeks of trying to catch the waiter’s eye if the meal he eventually brings you is so exactly what you ordered?