Guañape Sur is a hostile, rocky island off the coast of Peru. It is a barren, waterless place, yet it is home to hundreds of thousands of birds. Two guardians are allowed to live on Guañape Sur for ten years. On the eleventh year, however, hundreds of workers arrive to collect the bird droppings, guano, which are used to make fertiliser and dynamite. A war has even been fought in its name. Collecting the guano from the sharp rock is an arduous task, even in peaceful times, as the whole island has to be scraped by hand.