PERU: One of the keys to the Inca Empire’s prosperity was bird guano harvested from islands off coastal Peru and northern Chile. The waste from seabirds such as cormorants and pelicans was an excellent fertilizer and was transported to the Inca highlands and other less fertile areas to boost agricultural productivity. The Inca even implemented stringent restrictions to safeguard the birds’ breeding grounds, and violations were punishable by death. Researchers say this may be the earliest conservation scheme created by humans to protect an animal species and its natural habitat.