FOOTLESS AND FANCY FREE

Apus apus and the Future of History

by Simon Whitechapel

What’s the most advanced form of life? Well, as an old radio panellist called Professor Joad used to say, it depends what you mean by “advanced”. Take it in one particular way and I think there’s a good argument for the most advanced form of life being Apus apus, or the Common Swift.

Here’s the argument. The history of life has been the history of adaptation to new environments. First came the sea, then the land, then the air, with millions of years in between. In fact, the move from sea to land took even longer: according to the American biologist Edward O. Wilson, “[t]hree billion years ago the land was virtually devoid of life”, and it wasn’t until “the late Ordovician period, 450 million years ago” that the “first plants ... invaded the land”.¹

Animals followed, and among the animals were, sooner or later, the insects, the most successful group of multicellar organisms ever to appear. Part of the reason for their success is undoubtedly their ability to fly. They were the first to adapt to a wholly new environment: the air.² Vertebrates took a long time to follow: insects were flying by about 300 million BP (before the present day), reptiles by about 230 million BP, and mammals by about 50 million BP.³

Though insects as such first appeared about 500 million BP. Reptiles and mammals were similarly tardy, because flight is difficult. It takes energy to get into the air and it usually takes energy to stay there, and it takes concentration to do both. Most animals that got airborne probably did so gradually, first learning to glide a little, then to glide a lot, then to flap even more, and finally, to fly for as long as they wanted.

But no animal has ever wanted to fly for ever: there are exclusively aquatic species and exclusively terrestrial ones, but no exclusively aerial one. If there were, it could be said to be the most advanced species on earth, because it would have finally conquered the last and most difficult of all environments, the air. And that’s why I argue that the swifts are the most advanced species on earth, because they are the closest there’s ever been to an exclusively aerial species. Perhaps they’ll get there one day too, but for the time being they still occupy a position similar to that of, well, the toads.

Which probably sounds a little odd. After all it would be hard to find two kinds of vertebrate more unalike than toads and swifts. Toads are earthbound, warty, squat, ungainly, and sluggish. Swifts are airborne, sleek, delicate, graceful, and eponymously swift. The only obvious things they seem to have in common is that they’re both animals with backbones that eat insects and lay eggs.

But no, I think there’s something more. Toads and swifts are both reluctant amphibians. In the strict, etymological sense, that is, because amphibian means “living two kinds of life”, from the Greek amphi- “of two kinds” and bios, “life”. Toads live on land and return to water only to breed. Swifts live in the air and return to earth only to breed. And when I say “live in the air”, I mean exactly that. David Attenborough remarks of the swift that

So extreme is its adaption to an aerial existence that its feet are reduced to little more than tiny grasping hooks. Its scimitar-curved wings are so long that sitting flat on the ground it cannot beat them properly and it can only get into the air with any ease by launching itself from a cliff or the side of its nest. ... They never alight between breeding seasons so that they spend at least nine months of the year continuously on the wing.⁴

True, sooty terns (Sterna fuscata) remain continuously aloft for longer – 3-4 years⁶ – but they do so over water, which is less remarkable, and they are not so completely adapted to enormously prolonged flight: there are no obvious clues to their remarkable abilities in their bodies and they eat fish, which are, of course, aquatic (and are caught, presumably, on fly-by at the surface). Swifts, on the other hand, eat flying insects and, as already mentioned, there are obvious clues to their abilities in their bodies. An ornithologist examining a swift for the first time would immediately remark its degenerate feet and probably be able to make a good guess as to what way of life they represented.

That’s why the scientific name of the swift is Apus apus: octopus means “eight-foot” and apus means “no-foot”, from the Greek a-, “without”, and pous, ”foot”. Micropus (”tiny-foot”) would be more appropriate, and was in fact once used, but at least the scientific misnomer stands in a long tradition:

A small bird very frequently used in arms is the swallow, known heraldically as the martlet. It is generally drawn without proper feet ... The skimming flight of swallows gave rise to the popular belief that they never perched anywhere, because they had no feet to perch on.^6a

The sea, to be sure, is a large department; and that is how it succeeded in attracting Swinburne’s attention; for he seldom noticed any object of external nature unless it was very large, very brilliant, or very violently coloured. ... [His] metaphors and similars are perpetually repeated. They are derived from the few natural objects which he had noticed: the sea, the stars, sunset, fire, and flowers, generally of a red colour, such as the rose and poppy.⁷

Which are neither large nor ferocious. Nor edible, like heraldic fish, or useful, like heraldic bees. The appearance of swifts in heraldry is therefore something of a mystery and the usual explanation may have arisen after the fact: it was said that a martlet was used for a younger son’s coat-of-arms because its footlessness symbolized his inability to inherit, and walk on, his ancestral lands.

Elsewhere in history, however, swifts may help to clear up a mystery rather than create one. The mystery is that of the Messerschmidt 163, or Komet, which was as remarkable in its way as the swift still is in its:

The most radical aircraft to see action in World War II, the Me 163 coupled innovative design features with a futuristic powerplant to produce a bold new type of short-range interceptor. The rocket-powered Komet featured a short fuselage and a tail with no horizontal section. After takeoff, the landing gear assembly, which was mounted on a trolley, was jettisoned at an altitude of twenty to thirty feet ... [and] the Komet would land on an extendable skid with a shock-absorbing leg.⁸

The chief drawback of the Me 163 was the volatility caused by its two rocket propellants ... Sometimes a Komet would explode while merely sitting a runway!⁹ ... [T]he landing impact often sloshed residual propellants together causing a violent explosion. Many aircraft were lost this way, and the original test pilot, glider champion Heini Dittmar, was badly injured when the skid failed to extend. ... in landing [e]verything had to be just right, because if the aircraft yawed, swung or ran too far on rough ground, it would turn over and the propellants explode.¹⁰

So why did what was, for its time, one of the most advanced pieces of technology on earth fail to take advantage of one of the most ancient? Perhaps because Dr Alex Lippisch (1894-1976), the designer of the Komet, was subconsciously influenced by the swift.

 

There are two other strong parallels between the aircraft and the bird besides this “footlessness” and clumsiness on the ground: their shape, speed, and aerial grace. Like the swift, the Komet had wings wider than its body was long: 9.3 metres (30'7") as against 5.69 (18'7"); and like the swift, the Komet was extremely fast: 960 km/h (596 mph) at 10,000 m (32,800 ft); and like the swift, the Komet, “in the air ... was beautiful”.¹¹

If one were setting out to build a mechanical equivalent of the swift, the Me 163 is pretty much what one might come up with. The final touch is that shared “footlessness”, very difficult to explain for the Me 163 in rational military terms, but explicable, perhaps, if Lippisch were, as I suggest, subconsciously influenced by the swift. It is, after all, the most aerially adapted of all birds and in some ways the most beautiful too, and anyone interested in flight would find it a fascinating creature.

Lippisch was certainly interested in flight and may also have been a Vogelfreund, or birdlover. One of his American counterparts, the rocket pioneer Robert Goddard (1882-1945), spent hours as a bedridden child birdwatching through binoculars, for example, and Lippisch himself, like many German flyers before Hitler broke the ban on military aviation, came to aeronautics through gliding, the purest and most birdlike form of flight, without noisy and outline-spoiling propellors or jet-intakes. As a rocket aircraft, the Komet lacked these too, and in essence it was a powered – or hyperpowered – glider:

gliding trials began with the Me 163 V1 in the spring of 1941. Again the tailless machine floated like a bird (the main snag being that instead of landing where the pilot wanted, it kept floating)... ¹²

Even the “taillessness” of the Komet might be read as a parallel with the swift:

The long, narrow scythe-like wings, streamlined body and short tail give the Swift its dashing outline in flight and separate it easily from the swallows and martins.¹⁴

But even if – as I suspect it will – the theory proves to be false or unprovable, it’s still interesting as an example of a coming discipline that might be called historology. Which is a blend of history, or the study of the past, and histology, or the study of body tissues. Histology comes from histos, the Greek for “web”, and a web is exactly what history is. A twitch at the edge (a fly caught on a strand of silk; a German schoolboy watching birds) can have big effects at the centre (the spider running out to investigate; the schoolboy growing up to design devastating but flawed warplanes for Adolf Hitler).

Because of our evolution, we human beings like to see history as the story of great personalities or great ideas, and historians tend to explain big events – the fall of the Roman Empire, say, or the later eclipse of southern Europe by northern – in political or demographic or ideological terms. The Roman empire fell because barbarian invasions coincided with the innervating effects of Christianity and the decadence of ruling classes; southern Europe was eclipsed because northern Europe acquired the Protestant work ethic.

It seems obvious that big events must have big causes. And they do – sometimes. But not always. There are much smaller explanations for both the big events just mentioned: that the Romans were poisoned by the lead in their water-pipes and that the medieval invention of hay allowed the cold north to overwinter its domestic animals more easily. A small change in one part of the historical web has a big effect elsewhere.

Which sounds like chaos theory, doesn’t it? A butterfly flaps its wings in China and a week later there’s a hurricance in Florida. And yes, there certainly seems great scope for applying chaos theory to history, but my new discipline of historology means something a little different. Chaos theory is about quantities and numbers; historology will be about qualities and facts as well. With an initial value of 1·000001, the equation x = x - 1/(x/2) yields -3·1882 after twenty cycles; with an initial value of 1·000002, it yields -12·0074. That’s chaos theory: small difference in initial conditions, big difference later on.

Historology won’t necessarily be about small changes. After all, the introduction of lead-piping or hay wasn’t really a small thing. Each must have affected huge numbers of people and in a much more intimate and complete way than politics or religion usually did. The problem is that lead-piping and hay don’t have much human interest, and human beings, naturally enough, like things to have human interest. We like things, for better or worse, to be the result of conscious decisions made with clear foreknowledge of what the effects will be. “What we are looking at is good and evil, right and wrong”, as George Bush Snr once droned.¹⁵ Lead-piping and hay don’t come under any of those categories.

Neither does my hypothetical swift-influence on Dr Alex Lippisch. Not directly. But it certainly has human interest, at least for birdlovers. What unites the historical influence of lead-piping, hay, and swifts is that it would be, first, unexpected and, second, invisible in any single narrowly focused discipline. Plumbing – we owe the name to plumba, the Latin for “lead”, in fact – is part of architecture, the toxic effects of lead part of medicine. It took a cross-fertilization of disciplines to produce that theory about the fall of the Roman Empire. Similarly, a cross-fertilization of political and agricultural history produced the theory about the rise of northern Europe, and a cross-fertilization of military history and ornithology produced my theory about the Me 163.

And that’s historology – explanation by synthesis. The trouble is that the possible range and number of syntheses are astronomical. Robert Graves gives some good examples of this in his introduction to the New Larousse Encyclopedia of Mythology:

A proper study of myth demands a great store of abstruse geographical, historical and anthropological knowledge; also familiarity with the properties of plants and trees, and the habits of wild bird and beasts. Thus an Central American stone-sculpture, a Toad-god sitting beneath a mushroom, means little to mythologists who have not considered the world-wide association of toads with toxic mushrooms or heard of a Mexican mushroom-god, patron of an oracular cult; for the toxic agent is a drug, similar to that secreted in the sweat-glands of frightened toads, which provides magnificent hallucinations of a heavenly kingdom ... Aphrodite the Greek love-goddess employed a scallop-shell for her voyages across the sea, because its two parts were so tightly hinged together as to provide a symbol of passionate sexual love – the hinge of the scallop being a principal ingredient in ancient love-philtres.¹⁶

This had long been a puzzle to Egyptologists, and they sought to explain it in traditional anthropocentric ways:

Menkaura [the builder of the third pyramid] was probably short of resources [or] in a hurry, so he built a smaller pyramid.¹⁷

And positioning and sizes are, of course, numerical concepts. But the concepts in Graves’ discussion of the links between mushrooms and toads aren’t – except in the final analysis. The concepts there are chemical structure and subjective experience: the mushroom “toxin” is chemically and psychoactively similar to the toad secretion. In the final analysis, however, chemical similarity is based on the spatial arrangement of atoms and molecules, and subjective experience can be reduced to numbers: we can ask questions like this: on a scale of one to ten, how similar is the experience of eating a mushroom to that of licking a toad?

So historology will be a mathematically based science and form of research, which is why it will be so powerful. First, because it will be able to be tested rigorously, and second because it will be able to be computerized. Even in its crudest form, such as the high-speed brute-force comparison of facts from widely separated disciplines, computerized historology will probably uncover historical and cultural patterns that have previously gone unnoticed, but those early successes may lead to the creation of theories of culture and behavior that approach the robustness of those in the hard sciences. In his How the Mind Works (1998) the American linguist Steven Pinker describes the discovery of uncanny parallels between societies based on caste but widely separated in space and time: their lack of a true history and so on. It appears that there are laws of culture at work: historology will help us to uncover more.

The prospect is exciting, but also disturbing. What will we discover? Where will we discover it? I don’t know, but I suspect – and hope – it will be in small things rather than large ones that flatter human vanity. After all, the largest form of life on earth, the blue whale, feeds on one of the smallest forms of life on earth: krill, or tiny planktonic crustaceans. Historological programs will roam oceans of information and, like the blue whale, may nourish themselves on the smallest things there, not the largest ones.

APPENDIX: Could the swift ever become an exclusively aerial species?

From the point of view of human beings, swifts seem to have a clear evolutionary target: to become exclusively aerial. From the point of view of swifts themselves, they probably don’t. As far as we know, evolution is not teleological: it doesn’t have targets for species to evolve towards, except in an indirect sense. If the climate gets warmer or hotter, for example, evolution does have a “target”: for a species to adapt better itself to increased heat or cold.

Swifts don’t seem to be in this position, and it’s debatable whether they would be better off as a hypothetical exclusively aerial species or as they are, mostly aerial but returning to earth to breed. I think myself they would be better off exclusively aerial, and there’s evidence of this in a curious ability possessed by their young: to enter a form of “torpor” during periods when no food is available to them. Adult swifts have to fly to feed themselves, but they, like other birds of similar size, do not fly during heavy rain. Other birds of similar size can literally sit out heavy rain in trees and so on; adult swifts have to out-fly it, skirting incoming bad weather and slipping back in behind it.

They fly enormous distances to follow the sun like this, and it can mean that swift nestlings go days without food. The torpor they enter at such times is presumably an evolutionary response to reduce the physiological costs of starvation. But it is unlikely it reduces these costs to nothing, so swifts, successful as they are, might become more successful if they could avoid the need to return to earth at all. Other costs – attacks by predators and nest parasites – would be avoided at the same time, for it may be significant that swifts are so strongly associated with human beings:

Most often found near towns and villages. Nests under eaves, in church towers, houses and very rarely in trees.¹⁸

Apus melba was larger than Apus apus before human beings began to build houses and towers, and presumably its habitat imposed fewer costs or bestowed greater benefits, or both. But the Alpine Swift too would presumably be better off exclusively aerial. If so, like its cousin, it would have to solve the problem of breeding in the air. Outside myth, where there are stories of mountains so high that an egg falling from one would hatch before it reached the ground, the only way for it to do this would apparently be to give birth in the air to live young.

Live young already able to fly, of course. But swiftlings, in a sense, are already able to fly when they hatch: when they are old enough to leave the nest, they leave it once and for all, and the neural mechanisms enabling them to do so must develop in nido without any direct experience of flight. If swiftlings could somehow be retained within the body of a female swift until this stage is reached, live birth in flight certainly seems possible. The problem remaining is that swifts would have to be, as far as I know, the first birds to become live-bearing: egg-laying has been universal among the many thousands of species of birds for millions of years.

But that there are certainly evolutionary pathways between egg-laying and live-bearing has been proved by fish, amphibians, reptiles, and, of course, mammals. Some fish, amphibians, and reptiles are live-bearing, and live-bearing mammals are descended from egg-laying ancestors (and a few archaic mammals, like the platypus, still lay eggs). Some newly-born mammalian young, indeed, are able to move like adults almost immediately: gazelles and wildebeest, for example. This is common among live-bearing fish and reptiles, and swifts, as we have already seen, already seem ready to join them if they can overcome that universal avian commandment of omnia ex ovo: everything from the egg.

But swifts (and hummingbirds, their cousins in the Apodiformes order) are already exceptional – indeed unique – among birds, and it’s interesting to speculate whether they have a higher mutation rate than the avian average. They’ve already acquired degenerate feet and juvenile torpor; perhaps live-bearing will be next. If they do have a higher mutation rate, perhaps it reflects something about their genetics or perhaps something about their environment. After all, swifts spend far more time in the air than most other birds, directly exposed for prolonged periods to mutagenic cosmic rays and solar radiation. The longer they flew, the more they mutated to allow them to fly longer. This may mean that the bargain they struck long ago with the powers of the air was an irrevocable one: they will either stay as they are or become more aerial still, perhaps to the point of remaining entirely in the air from the moment of their birth to the moment of their death.

Science fiction has anticipated this. Philip José Farmer once wrote about an alternative universe where another Christopher Columbus sets out to prove the earth is round – and fails, for the earth in this alternative universe is flat. Columbus’s hopes are raised just before the end when he sees birds flying above him and reasons that birds must mean land, for he fails to see that these birds have no feet and so need no land. The story is called “Sail On! Sail On!” – words that would serve, in German, as a suitable encouragement for the swift, because in German “sail” is segeln and swifts, as we have already seen, are Segler: sailors, or gliders, of the earth-cloaking ocean of the air. So perhaps swifts could one day be called upon to segeln für immer – to sail on for ever.

SwiftSite

A website devoted to the Common Swift.

ApusLife

The Virtual Magazine of the Common Swift

1. The Diversity of Life, Allen Lane, The Penguin Press, Harmondsworth, Middlesex, 1992, ch. 10, “Biodiversity Reaches the Peak”, pp. 183 & 190

2. But flight – à la flying fish – may first have been exploited by small sea-animals escaping predators before the conquest of land.

3. These dates are for true powered flight rather than simply gliding, and are estimated from references in The Evolution of Life, David John & Richard Moody, Macdonald, London, 1980.

4. Life on Earth: A Natural History, ch. 8, “Lords of the Air”, pg. 183

5. Guinness Book of Records, 1987, ch. 2, “The Living World”, “Birds”, entry for “Most Airborne”.

6. Though the ornithologist might think he was examining a crippled or otherwise abnormal specimen, of course.

6a. Heraldry, Rosemary Manning, A&C Black Ltd., London, 1966, ch. 9, “The Charges”, pg. 42

7. Housman’s article “Swinburne”.

8. Lucas Arts Air Combat Classics: Secret Weapons of the Luftwaffe, instruction manual, Victor Cross, 1991.

9. Ibid.

10. Hitler’s Luftwaffe: A pictorial history and technical encyclopedia of Hitler’s air power in World War II, Tony Wood/Bill Gunston, Salamander Books, London, 1977, entry for Me 163.

11. Ibid.

12. Ibid.

13. Thanks to Ulrich Tigges at the swift-website for help with these meanings.

14. Birds of Britain and Europe, Andrew Cleave, Reed Books, London, 1991, entry for “Swift”.

15. He was referring to the Gulf War, I think.

16. Op. cit., Hamlyn, Feltham, Middlesex, 1977, pp. vii & viii

17. Op. cit., ch. 5, “The Giza Plan”, sec. II, “An Architectural Plan”, pg. 113 of the 1995 Mandarin paperback.

18. Birds of Britain and Europe, entry for “Swift, Distribution and habitat”, pg. 154

© 2004 Simon Whitechapel