Mother Nature's humdingers: The awesome animals that turn the laws of science upside down



Even by the miraculous standards of the natural world, it’s a feat almost beyond imagining.



Scientists in California have shown that a small bird known as Anna’s hummingbird, when attempting to impress a mate, can dive through the air at speeds of around 50 miles per hour.

So far, so what? After all, even a humble Ford Fiesta can go at least twice as fast. Ah, but an Anna’s hummingbird is only five inches long.

A scientific study, published this week, has shown that if you scaled it up to the size of a Ford Fiesta (13ft) it would be going at 1,300 miles per hour - almost twice the speed of sound.



Marvel: The Anna's Hummingbird can beat its wings 1,000 times a minute



Indeed, if you calculate speed using body lengths per second (the number of times an object can travel its own length in one second), the figures are even more astonishing.

A fighter jet can travel at 150bl/sec; the Space Shuttle at its fastest reaches 207bl/sec; but when it’s diving, the Anna’s hummingbird tops the lot at 383bl/sec.

Awesome indeed. Especially when you consider how the little creature does it.

To perform its astonishing dive, the hummingbird must whirl its wings at more than 1,000 beats a minute and burn body fuel — derived mainly from nectar — about 400 times faster than a human.

If we metabolised as quickly as they do, we would create such extreme body heat that we’d roast ourselves alive.



A male Anna's hummingbird captured caught during a display dive, compiled from high speed video.

Furthermore, Anna’s hummingbirds can do another incredible aerial stunt — it sticks out its wings when it’s about to hit the ground and zooms upwards again.

The resulting G-force (its acceleration relative to freefall) is about nine times the force of gravity — enough to cause any normal creature, even a trained fighter pilot, to blackout.

All in all, you’d be forgiven for thinking that this little fellow must rank as one of the most incredible creatures on the planet.

But, in fact, there are many, many members of the animal kingdom whose physical capabilities simply beggar belief — indeed, they seem to defy the laws of physics, and thus of nature itself.

Such miracles can be seen in even the simplest creatures.

When I was at school, we were solemnly taught that no living organism could survive at temperatures much about 40C. (Birds commonly do operate at about 40C, but humans prefer a more modest 37C and are feverish at 40C.)

Then scientists in Yosemite National Park in California began looking for bacteria in the hot springs, where the water wells up under pressure at more than 100C — hotter than boiling water at normal atmospheric pressure.

It seemed a ridiculous place to look for living creatures, but sure enough, the scientists found microbes in huge variety.



Don't suffer the bends: Sperm whales can dive to depths of 3,000 metres

Later, more such thermophiles — heat lovers — turned up in the volcanic hot springs that well up from the beds of the world’s deepest oceans. Scientists thought they were very odd — the world’s most extreme heat specialists.

Now, it seems likely that the very earliest of all earthly creatures were thermophiles. In other words, it’s not the hot-spring creatures who are odd.

We are the strange ones: the creatures who have learned to be much cooler than what was once the norm, many millions of years ago.

So, how do the thermpophiles do it? After all, all living creatures are made largely of protein — and protein cooks at not much above 40C. (Hence why, in some extreme cases, marathon runners start damaging their own kidneys as their body overheats.)

The answer is: no one really knows. It’s an unfathomable mystery that even the finest scientific minds cannot (yet) explain.

Nor is this nature’s only trick.

Pressures in the deep oceans exceed imagining.

At 700m — fairly modest depths by ocean standards —the pressure is up to 20 times normal atmospheric conditions.



Keeping warm: Emperor penguins survive -50C cold by huddling together

In the very deepest oceans, it’s more than 1,000 atmospheres — enough to crush every bone and organ in our bodies.

Yet still some species of deep sea fish can survive here. They do so by having no internal body cavities — not even swim bladders, which many fish use to keep them stable underwater — so there is nothing to collapse.

But get this: the sperm whale can dive to depths of nearly three kilometres (nearly two miles) where the pressure reaches hundreds of atmospheres — and yet it’s an airbreather, and so it has lungs. Why isn’t it crushed?

The answer is that the sperm whales’s ribs are highly flexible — and when the lungs collapse as they must, the ribs simply flatten with them. The oxygen, meantime, is stored in the blood — and the sperm whale can dive for up to 90minutes at a time without needing to surface for breath.

But there is one more problem. If human divers rise too fast from depths far more modest than this, they get the bends.

This happens when nitrogen gas dissolved in their blood comes out of solution as the pressure is reduced and so forms bubbles in the bloodstream, which can be fatal. This ought to happen to whales, too. But it doesn’t. Again, naturalists are not clear why.

At the other end of the pressure scale, high above the Himalayan mountains, you may encounter skeins of migrating bar-headed geese, happily flying at almost the same height as jumbo jets.

The air is thin — that’s why human mountaineers at comparable heights need oxygen — and the temperature is colder than Siberian winter.

High-fliers: Bar-headed geese can soar to the level of Jumbo Jets

But the geese revel in it. The thin air offers less resistance — just as it does to a jumbo jet — and the extreme cold prevents over-heating.

More stoically but equally impressively, male Emperor penguins tough out the Antarctic winter, where temperatures regularly plunge below minus 50C, by standing for weeks in a huddle, the outermost ones forever shuffling to the inside so that everyone takes their share of the furious, cutting winds.

It is a masterclass in tribal cooperation.

Polar fish, meanwhile, produce their own natural anti-freeze — chemical compounds that stop them being frozen stiff in the icy depths.

But often it’s the behaviour of animals that is even more astounding than their physical characteristics.

You might, for example, think it would be utterly impossible for any creature to catch moths on the wing at night in the pitch dark — but bats do it by echo-location, using highpitched squeaks which bounce off their surroundings to create a ‘mental picture’ so detailed that they can even pick out a tiny flying insect.

For good measure, new research shows that the echo-locating bats even listen out for other bats as well, so they don’t get in each other’s way.

Spiderman has nothing on bats.

It is equally impossible, you might think, for a baby bird that has done nothing in its brief life but sit in a nest and eat caterpillars to take off — after its parents have quit the scene — and fly from, say, Sussex to southern Africa: over the Channel and the Strait of Gibraltar; over the Sahara.

But that is what every new generation of swallows does — and then they repeat the feat, both ways, every year, for as long as they live, which could be a decade.

In fact, every autumn, about five billion birds take off from Northern Europe and Asia and head for the south, and about the same number take off from North America and head for Tropical America and beyond.

About 5,500 species — about half of all bird species — undertake some form of migration. On their first trip, some young birds simply follow their parents, but many, like young swallows, set out unchaperoned.

Yet how do they know where to go?



Natural protection:The polar fish can make its own anti-freeze

Again, no one really knows. Some birds, such as pigeons, seem to read the Earth’s magnetic signals: they have compounds of iron at the base of the beak that make them hypersensitive to magnetic changes.



Others use sight and smell. When they get close to their homes, pigeons apparently use their knowledge of the landscape and their sense of smell — first homing in on the general niff of ammonia that emanates from all bird colonies, then recognising the specific smell of their own flock.

Others seem to navigate by the sun — but not, presumably, the many small songbirds and others that prefer to migrate by night, avoiding over-heating by flying when it’s cool.

Night-flyers apparently navigate by the moon and stars. Some birds, like the indigo bunting, much favoured by scientists for behavioural research, evidently spend their early weeks in the nest learning the layout of the night sky.

They do not need to be quite so knowledgeable as the ecologist Patrick Moore. They just need to be able to identify the pole star — the one that all the other stars seem to revolve around. That, apparently, is enough for orientation. But still it is astonishing.

What, then, with all these feats to choose from, is the most remarkable creature of all? Which one would it be hardest for an engineer to mimic?

Well, despite the extraordinary competition, there is one familiar creature that could put in the strongest bid to be the most astonishing of all: you.

The most mundane of tasks undertaken by humankind requires truly astonishing skills and computing power.

Never mind the Shakespeares, the Mozarts and the Einsteins — we are, all of us, miracles of nature.

Don’t believe it? Think on this. We dream that one day sophisticated robots will be invented that could take the grind out of life’s daily chores.

But a robot that could carry a tray of tea upstairs, while whistling a happy tune and thinking about plans for tomorrow would need an onboard computer that would make the whole of Nasa’s hardware look like a pocket calculator.

Yet you or I could do it in an instant. We are more sophisticated, more intelligent, more marvellous than any man-made invention.

But we take such stuff for granted.

Anna’s hummingbird, and its death-defying flights of fancy, may seem awesome, but in truth, all life is wondrous.

We should appreciate our fellow creatures far more than we do. Especially ourselves.