These population figures do not take into account the El Ni o of 1997-98, which had a devastating affect on Humboldt penguins. During El Ni o periods, cool, nutrient-rich waters warm, forcing prey species of fish to go elsewhere in search of food. As a result, penguins die of starvation. The primary reason Humboldt penguins are endangered is due to humans. The guano in which Humboldt penguins make their nests is a valuable fertilizer used in agriculture.
Humans disrupt the penguins by removing and destroying the guano during nesting season.
Humboldt penguins also must compete with the offshore fishing industry in Peru and Chile and they often get caught in fishing nets and drown. Other threats to Humboldt penguins are oil spills, humans collecting their eggs for food, disturbances caused by tourists and researchers, and introduced predators such as rats, cats and dogs. This program works to increase the number of healthy captive Humboldt penguins. Woodland Park Zoo also works to educate the public about Humboldt penguins and this is the first step to conservation. About 230 Humboldt penguins survive in captivity in North America.