Unveiling an Important Humboldt Penguin (Spheniscus humboldti) Breeding Colony in Perú and the Need for Its Protection Against the Potential Impact of Guano Harvest

Abstract

Abstract. Humboldt Penguins (Spheniscus humboldti) are globally Vulnerable due to the decline of the population and to a decline in the number of breeding sites in comparison to historical records. In 2010, we observed a few thousand Humboldt Penguins nesting in a surface-nest colony on Isla Santa Rosa in southern Peru. This number was unexpected because this site has never been listed as an important Humboldt Penguin breeding ground. We visited this island again in June 2011 and 2012, and counted 1,965 and 1,745 active nests, respectively. These numbers indicate not only the presence of at least 3,500–4,000 Humboldt Penguins, but places Isla Santa Rosa among the five largest Humboldt Penguin colonies within its entire range. The need for recognition of Isla Santa Rosa as a major Humboldt Penguin refuge is crucial for the conservation of the species, as the island has remained untouched from guano harvesting since 1996. This has resulted in a significant accumulation of guano likely to be legally collecte...