After breaking off from the African continent, Madagascar developed in total isolation for millions of years, giving birth to distinctive species. When the first colonists arrived two thousand years ago, they exterminated most of the big animals over a very short period of time. Nevertheless, the island is still one of the largest natural sanctuaries in the world with thousands of species. However, Madagascar is in danger as its forests are vanishing at a frightening rate - three quarters of it have already disappeared.