6/9. Madagascar: a Treetop Odyssey The virgin rainforests of Madagascar support some of the rarest species on Earth - 75 per cent are found nowhere else in the world. Much of this remarkable diversity is found in the forest canopy, which has been virtually inaccessible to scientists - until now. They're using ingenious methods - including a giant inflatable raft and a metal tree house - to explore a potential treasure trove of biochemical resources. Horizon follows their fascinating work - and an expedition that's not without its dangers.
Producers Milia Harrison-Hansley , Luc Marescot , Antoine de Maximy Editor Andrew Cohen www.bbc.co.uk/horizon