Science Authors

"And they noticed what few others had done – that all over the world, charismatic animals that were once numerous were beginning to disappear. The Arabian oryx, which once had been widespread all over the peninsula had now been reduced to a few hundred. In Spain, there were less than a hundred imperial eagles. The Californian condor was down to about sixty. In Hawaii, a goose that had lived in flocks on the lava fields around the great volcanoes were reduced to fifty. The strange little rhinoceros that lived in the dwindling forests of Java – to about forty. Wherever you looked there were examples of animals whose populations were falling rapidly. This planet was in danger of losing a significant number of its inhabitants – both animals and plants."

"I'm very aware that this programme may be regarded as bleak or depressing - an increasing population with an ever decreasing supply of resources – but humans have capabilities that animals don't: to think rationally; to study; to plan ahead. The number of people on the planet depends on the personal decisions we each make regarding the number of children we have even setting aside the moral responsibility we have to protect other species, if we continue to damage our ecosystem, we damage ourselves. Its clear that we'll have to change the way that we live and use our resources. We're at a crossroads where we can chose to cooperate or carry on regardless. Can our intelligence save us? I hope so. m46s24-m47s15"

"It seems to me that an understanding of the natural world is crucial for all of us – after all we depend upon it for our food, for the air we breath and, some would say, for our very sanity. Its a relationship that we're stretching to breaking point as we continue to grow in numbers. m44s31-m44s57"

"For most people the idea of someone else telling them how many children they should have is simply unacceptable so when governments attempt to do just that it always causes controversy. In 1979 the Chinese government introduced its infamous one-child policy, changing family life in China forever. Families were encouraged to have fewer children. Those that didn't were fined. The policy was a direct response to the preceding decades of famine and starvation. It's still in place today. According to official figures, without the one-child policy, there'd be four hundred million more people in China, that's more than the entire population of the USA. Its unlikely that other governments could undertake such an extreme path without major civil opposition. In the 1970s the Indian government also sought to bring down its birthrate. To start with it took a less aggressive path, setting up festivals around the country where vasectomies were carried out for small incentives. m31s56"

"As I see it humanity needs to reduce its impact on the Earth urgently and there are three ways to achieve this: we can stop consuming so many resources, we can change our technology and we can reduce our population. We probably need to do all three. m31m37-m31s56"

"In Rwanda children inherit land from their parents but in a country where the average family has more than five children that can only mean one thing – smaller parcels of land to live off. m30s00-m30s12"

"Just as the human population was starting its unprecedented growth spurt in the late eighteenth century, this was published. It's a first edition of an essay on population by the English clergyman Thomas Malthus. Malthus made a very simple observation about the relationship between humans and resources and used it to look into the future. He pointed out that "the power of population is indefinitely greater than the power of the earth to produce subsistence for man. "Food production can't increase as rapidly as human reproduction. Demand will eventually outstrip supply. Malthus goes on to say, if we don't control human reproduction voluntarily, life could end in misery, which earned him a reputation as a bit of a pessimist. But Malthus' principle remains true. The productive capacity or the Earth has physical limits and those limits will ultimately determine how many human beings it can support. m10s58-m12s18"

"Human beings are good at many things, but thinking about our species as a whole is not one of our strong points. m4s45-m4s53"

"I support a group called the Optimum Population Trust which campaigns to reduce birth rates because I think, if we keep on growing, we're not only going to damage nature but we're likely to see even more inequality and human suffering. m4s08-m4s43"

"I can't pretend that I got involved with filming the natural world fifty years ago because I had some great banner to carry about conservation - not at all, I always had a huge pleasure in just watching the natural world and seeing what happens. - I made those films because it was a hugely enjoyable thing to do. But as I went on making them it became more and more apparent that the creatures that were giving me so much joy were under threat. The fun is in delighting in the animals but if you do that you owe them something so you have an obligation to speak out and to do what you can to protect them. m3s08-m4s05"

"I was born into a world of just under two billion people today there are nearly seven billion of us. Whenever I hear those numbers I can honestly say I find it incredible, triple the number of human beings in what seems like the blink of an eye and the world transformed utterly. Human population density is a factor in every environmental problem I have ever encountered, from urban sprawl to urban overcrowding; disappearing tropical forests to ugly sinks of plastic waste, and now the relentless increase of atmospheric pollution. I've spent much of the last 50 years seeking wilderness filming animals in their natural habitat and, to some extent, avoiding humans. But, over the years, true wilderness has become harder to find. m1s58-m3s03"

"Today we're living in an era in which the biggest threat to human well-being, to other species and to the Earth as we know it might well be ourselves. The issue of population size is always controversial because it touches on the most personal decisions we make, but we ignore it at our peril. m0s50-m1-13"

"This is the Earth - our planet, home to millions of different species, but only one species dominates everything - human beings. There are nearly seven billion of us living on the Earth, and the human population is increasing by more than two people every second; two hundred thousand people every day; nearly eighty million people every year. Each additional life needs food, energy, water, shelter, and hopefully a whole lot more. m0s0-m0s43"

"Reptiles and amphibians are sometimes seen as simple, primitive creatures. That's a long way from the truth. The fact that they are solar-powered means that their bodies require only 10% of the energy that mammals of a similar size require. At a time when we ourselves are becoming increasingly concerned about the way in which we get our energy from the environment and the wasteful way in which we use it, maybe there are things that we can learn from "life in cold blood.""

"Reptiles and amphibians are sometimes thought of as primitive, dull and dimwitted. In fact, of course, they can be lethally fast, spectacularly beautiful, surprisingly affectionate and very sophisticated."

"If we and the rest of the backboned animals were to disappear overnight, the rest of the world would get on pretty well. But if they were to disappear, the land's ecosystems would collapse. The soil would lose its fertility. Many of the plants would no longer be pollinated. Lots of animals, amphibians, reptiles, birds, mammals would have nothing to eat. And our fields and pastures would be covered with dung and carrion. These small creatures are within a few inches of our feet, wherever we go on land – but often, they're disregarded. We would do very well to remember them."

"An eye from another world; a smell-detector, investigating the path ahead. We don't often see a snail that way, and that's because we've only recently had the tiny lenses and electronic cameras that we need to explore this miniature world. But when we meet its inhabitants face to face, we suddenly realise that their behaviour can be just as meaningful to us as the behaviour of many animals more our own size."

"Three and a half million years separate the individual who left these footprints in the sands of Africa from the one who left them on the moon. A mere blink in the eye of evolution. Using his burgeoning intelligence, this most successful of all mammals has exploited the environment to produce food for an ever-increasing population. In spite of disasters when civilisations have over-reached themselves, that process has continued, indeed accelerated, even today. Now mankind is looking for food, not just on this planet but on others. Perhaps the time has now come to put that process into reverse. Instead of controlling the environment for the benefit of the population, perhaps it's time we control the population to allow the survival of the environment."

"Warm-bloodedness is one of the key factors that have enabled mammals to conquer the Earth, and to develop the most complex bodies in the animal kingdom. In this series, we will travel the world to discover just how varied and how astonishing mammals are."

"Sensing the approaching danger, the snail flees. But in a world of snail paces, the conch is something of a Ferrari. It calls for desperate measures. Exhausted by the effort of its last-ditch attempt, the tulip snail is slowly... gunned... down."

"Birds were flying from continent to continent long before we were. They reached the coldest place on Earth, Antarctica, long before we did. They can survive in the hottest of deserts. Some can remain on the wing for years at a time. They can girdle the globe. Now, we have taken over the Earth, and the sea, and the sky. But with skill and care and knowledge, we can ensure that there is still a place on Earth for birds in all their beauty and variety, if we want to, and surely, we should."

"All over the world, birds [...] manage to survive in the most hostile of places. A century ago, a completely new kind of environment appeared on Earth. Nothing like it had faced birds before in their entire 200 million year history. Yet some species began to adapt to it almost immediately... The modern city."

"[African Rift Valley soda lakes]. Steaming-hot water comes from volcanic springs and is so loaded with soda that around the margins of the lake it solidifies into white curds. Yet flamingos come here in thousands. [...] The fact that so few creatures can tolerate these conditions means that any animal that can, has the place to itself and so can proliferate in vast numbers."

"No sooner has one been pushed out of the nest then a second will follow, until there is only one left. And that's what happens nearly always in a pelican's nest. That being the case, it seems rather inefficient, not to say heartless, that the pelican should always lay three eggs. But the reason is that it's partly an insurance policy, in case something terrible happens to one or two of the chicks, there's always a third left to carry on. And partly because, very rarely, when the fishing is very good, it is possible to raise more than one chick."

"Each [pelican] has already survived many perils in its young life. As a chick, it fought battles with its brothers and sisters and won."

"The battle between cuckoos and other birds is a continuing one. The cuckoos developing new stratagems and perhaps finding new victims, and the victims finding new defences."

"You might think that a hornbill would have the most powerful excavation tool of all, but in fact its huge beak is a relatively delicate structure and no use at all as a chisel."

"To many of us, however, this is the most delectable of natural sounds. It's an hour before dawn, it's spring, this is an English woodland. All around, the dawn chorus. It's so familiar that perhaps we take it for granted."

"Penguins underwater look somewhat like dolphins, and indeed the two families have similar evolutionary histories. Dolphins are descended from air-breathing land animals, just as penguins are descended from air-breathing flying animals. Both subsequently took to swimming for their food. They became beautifully adapted and streamlined. And now, both are superlative swimmers and highly accomplished fishermen."

"Members of the auk family, such as these guillemots and puffins... propel themselves, not with their feet like ducks, but with their wings, and they have paid a considerable price to be able to do so... Auks have had to evolve shorter, stubbier wings. That gives them a rather clumsy, whirring flight in the air, but it does enable them to "fly" underwater so well that they can outpace small fish."

"Mallards must be one of the most familiar birds in the world. Because of that, perhaps we tend to take ducks for granted. But in fact, they are a very varied family."

"The food-chain that sustains a meat-eater could scarcely be shorter than it is here. [...] Algae that can uniquely tolerate these salty waters proliferate in the sunshine by the ton. Flamingos filter the algae from the water with their beaks, and vegetable is turned into flesh. And that flesh is food for eagles."

"Even though hunters have a formidable armoury and great skill, most of their hunting trips... end in failure."

"Those that live in the air have to fight in the air."

"It's equally astonishing that the birds are able to measure its relative strength with such accuracy that they can trace it back to its source simply by sensing in which direction it becomes marginally stronger. But a turkey vulture is exceptionally well-equipped among birds, with wide-open nostrils and extremely well-developed sense organs within them."

"A spider. Quite big enough and succulent enough to provide a snack for a Scops."

"Living on the bodies of mammals, oxpeckers manage to get quite a varied diet. A maggot here, a tick there, a little sip of blood, perhaps a little tasty earwax."

"I'll bet when our prehistoric ancestors first dug for tubers and planted seeds in Europe, one of these little robins appeared within a couple of days. Other animals must have done the same job for them before human beings did. Once, not so long ago, wild pig were common all over Europe, and they're great diggers and rootlers. So maybe the robin's boldness and friendliness with other kinds of animals started in prehistory, even before human beings arrived in Europe."

"Without thermals, [raptors] can't travel far. But the snow geese fly on... They navigate by the stars."

"As the last thermals of summer start to rise, the birds [hawks and vultures] circle up to great heights, 10,000 feet or more, to give themselves a good start for the long journey ahead. As they glide southwards, slowly losing height, they will look for another thermal and make for its base so that, once again, they will be lifted high enough to reach the next."

"Its heart that in flight contracted a thousand times a minute, slows until its beat is virtually undetectable. Its body temperature falls dramatically, and its breathing seems to cease altogether. [...] It's hibernating; but for a hummingbird, winter comes 365 times a year."

"How is it that [birds] can withstand the pull of gravity that keeps the rest of us tied so firmly to the ground? The secret is a wing with a thick, rounded front edge that curves gently downwards toward the back edge which is very thin. As thin, in fact, as a feather. As the bird glides forward, the air flowing under the wing is impeded by the wing's downward curve so it becomes slightly compressed, and that pushes the wing up. At the same time, the air flowing across the top of the wing is deflected upwards by the wing's front edge, so reducing its pressure. If the air is moving fast enough, then the slight suction from above, combined with the push from beneath will be enough to lift the bird into the air [...] and ample to keep it aloft."

"[The Kiwi.] It's the bird equivalent of a badger."

"Many of New Zealand's birds flew here from Australia fifteen hundred miles away across the sea to the west. They started to do so millions of years ago, and they are still doing so today... So, if you know Australian birds, you will recognise quite a lot, particularly those that are relatively recent arrivals."

"The island is immense. It's 1,000 miles long, if you discount a narrow arm of sea that crosses it in the middle, and it contains mountains over 12,000 feet high. It's New Zealand. The first land-living mammals to get here were human beings and they didn't arrive until a mere 1,500 years ago. So here you can glimpse what the world would have been like if the birds had won that battle with the early mammals and now ruled the Earth, for here they once did."

"Birds are the most accomplished aeronauts the world has ever seen. They fly high and low, at great speed, and very slowly. And always with extraordinary precision and control."

"Wallace's emotions on discovering such marvels must surely be echoed by all of us who follow him. This is what he wrote: "I thought of the long ages of the past during which the successive generations of these things of beauty had run their course. Year by year being born and living and dying amid these dark gloomy woods with no intelligent eye to gaze upon their loveliness, to all appearances such a wanton waste of beauty. It seems sad that on the one hand such exquisite creatures should live out their lives and exhibit their charms only in these wild inhospitable regions. This consideration must surely tell us that all living things were not made for man, many of them have no relation to him, their happiness and enjoyment's, their loves and hates, their struggles for existence, their vigorous life and early death, would seem to be immediately related to their own well-being and perpetuation alone.""

"Ever since we arrived on this planet as a species, we've cut them down, dug them up, burnt them and poisoned them. Today we're doing so on a greater scale than ever […] We destroy plants at our peril. Neither we nor any other animal can survive without them. The time has now come for us to cherish our green inheritance, not to pillage it – for without it, we will surely perish."

"Midwinter, and the countryside is so still, it seems almost lifeless. But these trees and bushes and grasses around me are living organisms just like animals. And they have to face very much the same sort of problems as animals face throughout their lives if they're to survive. They have to fight one another, they have to compete for mates, they have to invade new territories. But the reason that we're seldom aware of these dramas is that plants of course live on a different time-scale."

"At a time when it's possible for thirty people to stand on the top of Everest in one day, Antarctica still remains a remote, lonely and desolate continent. A place where it's possible to see the splendours and immensities of the natural world at its most dramatic and, what's more, witness them almost exactly as they were, long, long before human beings ever arrived on the surface of this planet. Long may it remain so."