Newell’s Shearwater

Puffinus auricularis newelli / ‘A‘o
Newells shearwater
  • Found on Kaua'i from April-October
  • Endemic to the Hawiian islands and listed as Critically Endangered by the International Union for Conservation of Nature (IUCN)
  • The ‘a‘o is a medium-sized shearwater with a glossy black top, a white bottom, and a black bill that is sharply hooked at the tip. Its claws are well adapted for burrow excavation and climbing.
  • They feed primarily on squid and fish. They dive into the water to catch their prey, swimming down to a depth of up to 10 meters using their wings to move forward. They are attracted to schools of tuna and gather in flocks with other seabird species to catch prey driven to the surface by the tuna.
  • A single white egg is laid during the first two weeks of June. Both parents typically incubate the egg for 62 days. The young birds leave the nest in October, 88–100 days after hatching
  • The ‘a‘o was once abundant on all main Hawaiian islands. Today, they only nest in the mountainous terrain between 500 to 2,300 feet on Kaua‘i. This seabird was reported to be in danger of extinction by the 1930s. The introduction of the mongooses, rats, cats, dogs, and pigs have played a primary role in the reduction of ground nesting seabirds such as the ‘a‘o and the ‘ua‘u (Hawaiian dark-rumped petrel).
  • A second threat to the ‘a‘o is its attraction to light. Increasing urbanization and the accompanying manmade lighting have resulted in substantial problems for fledgling shearwaters during their first flight to the ocean from their nesting grounds. When attracted to man made lights, fledglings become confused and may suffer temporary night blindness. They often fly into utility wires, poles, trees, and buildings and fall to the ground. Between 1978 and 2007, more than 30,000 ‘a‘o fell on Kaua‘i’s highways, athletic fields, and hotel grounds.
  • Shearwaters are pelagic birds meaning they spend the majority of their life on the open ocean and only venture back to land to breed. Pelagic birds are powerful fliers with exceptionally long, thin wings. They can remain in flight for days or weeks, sleeping in-flight, while staying hundreds to thousands of miles offshore. They also have a special salt gland that helps them extract excess salt from their body via their nostrils. This allows them to drink seawater and ingest water from prey without accumulating toxic levels of salt in their bloodstream.
  • Kīlauea Point is trying to increase the breeding population on the refuge by installing artificial burrows and a sound system that broadcasts the sound of a large colony of ‘a‘o calls throughout the night. Overall, the ‘a‘o population is declining and Kaua‘i has greater than 80 percent of the entire population. The refuge is currently the only place where a colony is protected in perpetuity and there is active predator control. To learn more about this project and our partners click here.
  • ‘A‘o is a bird of the open tropical seas and offshore waters near breeding grounds. Their burrows are used year after year and usually by the same pair of birds. Although they are capable of climbing shrubs and trees before taking flight, ‘a‘o need an open downhill flight path to become airborne. Nesters begin arriving to Kīlauea Point at the beginning of April. ‘A‘o are synchronous breeders that will lay an egg in late May or early June. During their 9-month breeding season, they live in burrows under ferns on forested mountain slopes. 

Facts About Newell’s Shearwater

Length: 30-35 cm (12 -14 in), wingspan: 76-99 cm (30-35 in)

The ‘a‘o is listed as a threatened species and is protected under the endangered species act.