Catching butterflies in Kenya's 'sky island'

An international team of scientists has begun exploring one of the most isolated patches of tropical mountain forest in East Africa.

As well as finding more than 100 new plant species, and animals like rats, bats and tiny frogs, the researchers also recorded 125 butterfly species.

But the forest is also threatened by growing numbers of local herders, looking for new places to graze their cattle.

The BBC's Peter Greste joined the expedition and ventured into the forest with entomologist Dino Martins, to discover some unusual butterfly behaviour and meet a "vegetable dinosaur".