The Living World - Heath Fritillary

The Heath Fritillary butterfly was on the verge of extinction in Exmoor in 2001. Now, thanks to some targeted conservation work between the National Trust and Butterfly Conservation, this checkerboard-marked rare butterfly is increasing in numbers. Lionel Kelleway heads to a valley near Dunkery Beacon in the north of Exmoor National Park in search of one of Britain's rarest butterflies.