With a million species at risk of extinction, Sir David Attenborough explores how this crisis of biodiversity has consequences for us all, threatening food and water security, undermining our ability to control our climate and even putting us at greater risk of pandemic diseases. Extinction is now happening up to 100 times faster than the natural evolutionary rate, but the issue is about more than the loss of individual species. Everything in the natural world is connected in networks that support the whole of life on earth, including us, and we are losing many of the benefits that nature provides to us. The loss of insects is threatening the pollination of crops, while the loss of biodiversity in the soil also threatens plants growth. Plants underpin many of the things that we need, and yet one in four is now threatened with extinction. Last year, a UN report identified the key drivers of biodiversity loss, including overfishing, climate change and pollution. But the single biggest driver of biodiversity loss is the destruction of natural habitats. Seventy-five per cent of Earth's land surface (where not covered by ice) has been changed by humans, much of it for agriculture, and as consumers we may unwittingly be contributing towards the loss of species through what we buy in the supermarket. Our destructive relationship with the natural world isn’t just putting the ecosystems that we rely on at risk. Human activities like the trade in animals and the destruction of habitats drive the emergence of diseases. Disease ecologists believe that if we continue on this pathway, this year’s pandemic will not be a one-off event.
In the heart of Brazil lie the immense wetlands of the Pantanal--an area 10 times the size of the Florida Everglades. In the dry season, over 650 species of birds descend onto the shallow marshes to feast, breed, and raise their young, including the the regal jabiru, the colorful hyacinth macaw, and the noisy chacalaca.
The episode begins in the South American rainforest whose rich variety of life forms is used to illustrate the sheer number of different species. Since many are dependent on others for food or means of reproduction, David Attenborough argues that they couldn't all have appeared at once. He sets out to discover which came first, and the reasons for such diversity. He starts by explaining the theories of Charles Darwin and the process of natural selection, using the giant tortoises of the Galapagos Islands (where Darwin voyaged on HMS Beagle) as an example. Fossils provide evidence of the earliest life, and Attenborough travels a vertical mile into the Grand Canyon in search of them.
As the days shorten and the temperature drops, the inhabitants of Nunavik, Quebec prepare to face the approaching arctic winter. Watch as muskoxen fatten up, ptarmigans hunt for berries, and Inuit make use of the last warm days of the year.
Emus are unique: Native only to Australia, they're the second largest bird in the world and can trace their lineage back to the dinosaurs. When males incubate their eggs, they don't eat, drink, or even go to the bathroom until the job is done. Follow the fascinating life of this flightless bird as it stubbornly defies the odds by doing things its own way.
The Siamese fighting fish is so aggressive it will fight its own reflection until it is exhausted. Recent research shows that the fighting behaviour varies and depends on the personality of the fish! Male kangaroos were once pitted against humans in the boxing ring, with the most impressive male kangaroos being solid blocks of muscle with a kick that can kill. Why do they fight and what skills must a winner have?