Natural Wonders to See Before They Disappear (part 5)

Erosion is also a concern in Madagascar. The Betsiboka River, above, is red thanks to the large quantity of sediment it carries to the sea.

Photo: Courtesy oledoe/Flickr

Madagascar

More than 80 percent of Madagascar's flora and fauna are found nowhere else on Earth, thanks to millions of years of isolation in the Indian Ocean off of Africa.

The Threat: If nothing is done to save the world's fourth-largest island, its forests will be gone in 35 years (once 120,000 square miles, they're now down to 20,000), and their unique inhabitants along with them. Forest ecosystems are being destroyed by logging, burning for subsistence farms, and poaching. The 20 species of lemurs for which Madagascar is renowned are in danger of disappearing. Though there are game reserves, they're not large (occupying only five percent of the island), nor are they contiguous, thus failing to provide corridors for the animals to travel through. Some of Madagascar's endemic species have never even been recorded, and will likely be lost before they can be studied.