Sechura Bay, Peru’s largest, bites into the northwest Pacific coast south of the Ecuadorean border, enveloping the last remnants of the chilly, nutrient-rich Humboldt Current carrying water northward from the Antarctic. About 12 miles off the Illestas Peninsula forming its southern edge lies a small archipelago of islands that have supported huge populations of seabirds since time immemorial, nourished by the bounty of anchoveta fish in the surrounding seas. Over centuries, the birds deposited thick layers of nitrate-rich guano on the barren islands, which attracted people from the mainland to harvest and exploit the resource. The guano dwindled from over-harvesting and the islands have been once again remanded to their wild inhabitants. Conditions permitting, we can land on rocky Isla Lobos de Tierra and walk among the teeming colonies of Peruvian pelicans, Peruvian, Nazca and blue-footed boobies, guanay cormorants, kelp gulls and the noisy, active communities of sea lions that also gather on the shores. There are some buildings scattered around, relics of the boom times and abandoned since guano-mining ceased to be profitable.