A look at why a humpback whale would hold a diver hostage, how a colony of 1.5 million animals hide from the world in plain sight, and how a surprising stash of acorns could disrupt a whole town.
Richard Hammond continues his exploration of weird and wonderful animal abilities by focusing on super-senses, and discovers how those same animal senses have inspired some unlikely human inventions. Richard gets buried in a Californian gold mine, attempts to talk to a rattlesnake by telephone, and is taken for a ride by a monster truck that drives itself. Along the way, he encounters elephants who can talk to each other through solid rock; seals who use their whiskers to sense the shape, size, speed and direction of an object that passed over thirty seconds earlier; and a blind cyclist who relies on fruit bats to get him safely down a twisting mountain bike trail.
It is an unexpected and contrasting journey through America's iconic and varied landscapes as the Mississippi flows from source to mouth. The Mississippi's greatest surprise is its incredible reach. Its fingers stretch into nearly half of the USA, collecting water from 31 states. More than any other, this one river has helped unite the many and varied parts of America.
David Attenborough journeys to both Polar Regions to investigate what rising temperatures will mean for the people and wildlife that live there and for the rest of the planet. David starts out at the North Pole, standing on sea ice several metres thick, but which scientists predict could be Open Ocean within the next few decades. The Arctic has been warming at twice the global average, so David heads out with a Norwegian team to see what this means for polar bears. He comes face-to-face with a tranquilised female, and discovers that mothers and cubs are going hungry as the sea ice on which they hunt disappears. In Canada, Inuit hunters have seen with their own eyes what scientists have seen from space; the Arctic Ocean has lost 30% of its summer ice cover over the last 30 years. For some, the melting sea ice will allow access to trillions of dollars worth of oil, gas and minerals. For the rest of us, it means the planet will get warmer, as sea ice is important to reflect back the sun's energy. Next David travels to see what's happening to the ice on land: in Greenland, we follow intrepid ice scientists as they study giant waterfalls of meltwater, which are accelerating iceberg calving events, and ultimately leading to a rise in global sea level. Temperatures have also risen in the Antarctic - David returns to glaciers photographed by the Shackleton expedition and reveals a dramatic retreat over the past century. It's not just the ice that is changing - ice-loving adelie penguins are disappearing, and more temperate gentoo penguins are moving in. Finally, we see the first ever images of the largest recent natural event on our planet - the break up of the Wilkins Ice Shelf, an ice sheet the size of Jamaica, which shattered into hundreds of icebergs in 2009.
Liz meets the animal rebels who will stop at nothing to survive. From cockatoos vandalising houses in Sydney, to crabs who hold nemones hostage to protect themselves, it seems there are no lengths these animals won't go to. Liz sets out to see these animals in action, revealing the science behind their extreme behaviours. She meets the sloth whose disgusting hygiene habits may help hide it from predators, the stone martens who cause millions of pounds' worth of damage to cars to protect their territories and the chimpanzees who use bullying tactics to get to the top. As Liz discovers, when life in the wild gets tough, this outrageous behaviour could just be the key to survival.