Guano, << GWAH noh, >> is the waste matter of sea birds and bats. It makes a valuable fertilizer because it is rich in nitrate and phosphate. Large colonies of birds such as cormorants, gannets, guanays, pelicans, penguins, and petrels leave immense deposits of this material.
The islands off the coast of Peru have long been the chief source of supply. Deposits on the Chincha Islands at one time covered the surface to a depth of more than 100 feet (30 meters). Other valuable deposits lie on the Galapagos Islands of Ecuador. Deposits have been found in other parts of Latin America, on the Pacific Islands, and in the Grand Canyon Bat Cave in Arizona. See Peru (Mining) .
