Workers process bird dung on the Ballestas island, south of Lima
Workers process bird dung on the Ballestas island, south of Lima, October 8, 2011. Ballestas, as other 21 islands along the Peruvian coast, are home of nearly 4 million migratory birds as guanays, boobies and pelicans which excrement make up the world's finest natural fertilizer. The bird dung, also known as guano, reached its greatest economic importance in the 19th century as a coveted resource, being exported to United States, England and France. Nowadays Peru hopes to benefit mostly small farmers with an annual production of 20 thousand tons, destined to boost organic agriculture, according to Agrorural, the Rural Agrarian Productive Development Program. Picture taken October 8, 2011. REUTERS/Pilar Olivares(PERU - Tags: ENVIRONMENT AGRICULTURE ANIMALS SOCIETY) FOR BEST QUALITY IMAGE: ALSO SEE GF2E95H1KNW01.