Pink-footed Shearwater chick.
Photo: Peter Hodum

Overview
The Pink-footed Shearwater (Puffinus creatopus) is a species of seabird in the order Procellariiformes, a group of birds that includes albatrosses, petrels, shearwaters, diving petrels and storm petrels. Birds in this order are also called “tubenoses” because all but the diving petrels possess a pair of nasal tubes atop their bill. Tubenoses typically breed in colonies, usually on the same island on which they were raised. This group of seabirds is characterized by high adult survival, late age at first breeding, and low reproductive rates. They lay, at most, one egg per year and growth rates of chicks are amongst the lowest of any group of birds. Because of these characteristics, species in this order are extremely vulnerable to impacts that decrease adult survival. And because of their deferred age of first breeding and low reproductive rates, populations are incapable of recovering quickly, even under favorable conditions.

Pink-footed Shearwater resting at the entrance of an underground burrow. Adults lay eggs deep inside the burrow so a miniature infrared camera must be used to see if the burrow is actively being used to raise a chick.

Breeding
Pink-footed Shearwaters are colonial breeders, nesting in underground burrows that they excavate using their bill and feet. Burrows typically exceed 1m in length and sometimes extend for more than 3m. A burrow may be used for many decades, with each pair modifying the burrow to their liking. Like most tubenoses, Pink-footed Shearwaters maintain long-term breeding pairs. Established pairs return in late October-early November to the same burrow used in past breeding seasons. A single egg is laid in late November-early December, with both sexes sharing incubation duties. The chick hatches in late January-early February. After brooding the chick for its first few days, parents leave it unattended in the burrow to allow both birds to head to sea in search of food. Both parents feed the chick irregularly, with foraging trips lasting from 2-12 days. Chicks grow slowly, remaining in the burrow until they fledge in late April-early May. Once leaving the burrow, fledglings head directly to sea and are completely independent.

View of Isla Santa Clara, one of the breeding sites in the Juan Fernandez Archipelago, Chile.

Google maps:
Juan Fernández Archipelago
Isla Mocha

Distribution
The Pink-footed Shearwater is endemic to Chile, breeding on only three known islands. The largest known breeding population is found on Isla Mocha, a continental island, with smaller breeding colonies found on the oceanic islands of Robinson Crusoe and Santa Clara in the Juan Fernández Archipelago. During the nesting season, breeding birds remain in Chilean waters. After chicks fledge, shearwaters undertake an impressive migration northward to spend the non-breeding season in waters off the coasts of Peru and North America. In North America, they range along the Pacific Coast from Baja California, Mexico to British Columbia, Canada. Pink-footed Shearwaters appear to prefer the shallower, colder and typically more productive oceanic waters that occur over the continental shelf and shelf-break.

Population size
Due to limited information available about the size of breeding populations, the present global estimate of approximately 20,000 breeding pairs is tentative.

Photo: Peter Hodum

Diet and foraging
The diet of Pink-footed Shearwaters has not been well documented. Existing data indicate that they feed primarily in productive offshore waters over the continental shelf but also in pelagic waters, primarily on fish (sardines and anchovies), squid and small amounts of crustaceans. They capture prey by using shallow dives, up to 25m in depth but more commonly less than 3m, and by seizing items from the ocean surface.