The World Conservation Monitoring Centre say that cloud forests, which shelter thousands of rare species, are threatened by global warming.

They say the forests, which get water from clouds, and are found in Asia and South and Central America, are one-fifth smaller than they thought.

Global warming would make the clouds they depend on form higher up, reducing the area where the forests can grow.

The scientists think that farming, poaching, logging and road building are also threatening the forests.

As well as being home to rare animals, the forests' ability to take water from clouds means they produce lots of clean water for people to drink.