Natural World: Operation Pygmy Hippo

Solitary, secretive and extremely hard to find, the pygmy hippo is one of nature's last great mysteries and scientists know almost nothing about its life in the wild and what it needs to survive. This documentary follows Australian ecologist Wei-Yeen Yap as she heads to a remote part of the West African rainforest to investigate its life and habits, hoping to gain knowledge that will help save the animal from extinction. David Harewood narrates