How a Peruvian island is making money from bird poo
Guanape Sur island off northern Peru makes money from selling bird droppings - also known as guano. Commonly used in the 19th Century as a fertiliser, this organic product is making a comeback.
Two types of sea bird whose droppings produce guano - the Peruvian Booby and Guanay Cormorant - are protected. About 300 men live and work on the island for eight months of the year.
The guano is shipped off to organic farmers in Peru's mountains and jungle. Peru is the world's number one guano producer, with 30,000 tonnes a year.
Dan Collyns paid the island a visit.