BBC Wild South America 1of 6 Lost Worlds
The opening episode traces the events that have created the unique landforms and ecology of South America. Originally part of the supercontinent Gondwana, it broke away around 100 million years ago and became an island. At that time, it was dominated by reptiles and strange plants similar to the araucarias and tree ferns of Chile’s Valdivian forests. These forests also harbour descendants of the first mammals, small marsupials like the shrew opossum and monito del monte. Volcanic activity thrust up the Andes, where animals have had to adapt to the extreme environments of the altiplano and Patagonia. The Andes formed a natural barrier which altered the climate and the course of major rivers. Amazonia was once a great swamp, but now harbours the world’s greatest expanse of rainforest and its mightiest river. There are more species here than anywhere else, and many, including pygmy marmosets, have specialised diets. There are extreme dry environments here too. Guanacos survive in the Atacama Desert by eating lichens, whilst in windswept Patagonia, maras and burrowing owls squabble over the best nest holes. By contrast, the seas are rich in life: a pod of dusky dolphins is filmed attacking a shoal of anchovies. A land bridge with North America formed 3 million years ago, creating a pathway for invasive species. Those that survived were the opportunists like coatis, or specialists that exploited niches, like the maned wolf. Man, the most recent invader, has shaped the land and domesticated its animals to meet his own needs
