Neotropical Expeditions

The Peruvian Diving-petrel is the largest of five diving-petrel species found throughout the Southern Hemisphere. These seabirds have a characteristic whirring flight, barreling so low over the ocean's surface that they sometimes cut through the crests of tall waves. It lives in the cold waters of the Humboldt Current System, a nutrient-rich upwelling running along South America's west coast. The Humboldt Current is one of the planet's most productive ocean ecosystems, accounting for 18 to 20 percent of the total catch of sardines, anchovies, and jack mackerel worldwide. ⁣
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Underwater, diving-petrels use their short, powerful wings as paddles, propelling themselves as they search for small fish, squid, and zooplankton such as krill. Peruvian Diving-petrels have several other adaptations for hunting underwater, including an expandable gular (throat) pouch for storing food. Their genus name Pelecanoides derives from this feature, as it resembles the much larger pouch of pelicans. They have nostrils that open upwards rather than pointing forward, another adaptation for diving.⁣
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Once considered abundant, the Peruvian Diving-petrel has declined rapidly in recent decades due to a variety of manmade threats.⁣
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Photo by Jean Paul Perret⁣⁣ ⁣⁣⁣⁣⁣⁣⁣⁣

Inca Terns are best known by their dashing white mustaches, which are found on both male and female birds. The species is found only near the cold waters of the Humboldt Current, where the birds feed on anchovies and other small fish. Inca Terns feed by plunge diving and surface dipping. The birds also scavenge scraps from sea lions, dolphins, and fishing boats. The Inca Tern's elaborate courtship includes a "high flight," with the male quickly ascending to several hundred feet, pursued by the female. Pairs choose a nest site in cliff hollows or fissures—sometimes even in the old nest burrow of a Humboldt Penguin. They often return to the same nest site for several years in a row, and both parents incubate and care for the chicks.

Photo by Jean Paul Perret