More than a billion people around the world commute into cities each day, and they are not alone. The world's wildlife is commuting too. A steady flow of animals journey in and out of cities to find food and shelter or to start a family. Leaving the wilderness they must overcome the unique challenges that the urban world throws at them to benefit from the opportunities on offer. This episode explores whether the secret to an animal's success in this fast-changing world is to keep one foot in the wild and one in the city, becoming a wild commuter. It seems that all over the world animals are finding that the city can offer opportunities that are harder to come by in the natural world. Some, like African penguins, whose population has plummeted by 80 per cent in the last 50 years, find shelter in the city. By nesting in Cape Town they are safer from predators, and with relatively easy access to their fishing grounds they have the best of both worlds. Many other animals commute into cities because they are filled with food. In St Lucia, South Africa, that includes hippos. Able to eat up to fifty kilograms of grass in a single sitting, they have developed a taste for the short, manicured lawns and come to town every night to dine out. St Lucia's human residents have learnt to give the hippos the space they need during their night-time raids. Black bears need to eat more than 20,000 calories a day to survive their six-month hibernation through winter, and using their acute sense of smell they can easily track down leftovers. In North America they come into towns and cities in search of food. Many animals displaced from their natural habitat are now using their wild skill set in the city to help fulfill their needs. Could this be the beginning of a new and very modern migration?
Many of the great rivers of southern Africa start high up in mountain ranges, power their way eastwards across wild forests and grasslands, and eventually empty out into the Indian Ocean. Ride the currents of these powerful bodies of water as they reshape the lives of the wild animals who rely on them.
The Orange River travels almost two-thirds the length of South Africa to reach its most scenic checkpoint: The mighty Augrabies Falls. Widely regarded as one of the six great waterfalls on Earth, it is also an interminable source of hydration and food for the wildlife that live near its waters.
There is an electric grid submerged deep within the Amazon River, made up of a fascinating community of fish that have technological superpowers. Biologist Will Crampton ventures into this world, one which few have ever seen, on a mission to find, catch, and study electric fish. Armed with his own electric devices, join him as he uncovers the fighting style of the jaw lockers, the navigational skills of the knifefish, and the remarkable hunting technique of the electric eel.
2015 • Nature