Pacific Islands Fish and Wildlife Office
Pacific Region

Endangered Species in the Pacific Islands

Hawaiian Petrel / Pterodroma sandwichensis  / ‘Ua‘u

Hawaiian petrel The ‘ua‘u has a dark gray head, wings, and tail, and a white forehead and belly. It has a stout grayish-black bill that is hooked at the tip, and pink and black feet. This bird measures 16 inches in length and has a wing span of three feet. It has a distinctive call during breeding season that sounds like “oo ah oo.” They also have calls that sound like the yapping of a small dog.
Hawaiian petrel - Photo credit C. Hodges/HNP

Habitat & Behavior:
The ‘ua‘u is a bird of the open Pacific seas and has a high and steep flight pattern. Adults feed on squid, fish, and crustaceans and pass food to chicks by regurgitation. Breeding season is from March to October, during which time they nest in some of the main Hawaiian Islands, notably on Maui, Lana‘i, and Kaua‘i. They nest in burrows, primarily in remote montane locations, along large rock outcrops, under cinder cones, under old lichen-covered lava, or in soil beneath dense vegetation. The burrows are generally three to six feet long (from entrance to nest chamber), although some may be as long as 15 feet. One white egg is laid deep within the burrows.

Past & Present:
The ‘ua‘u was once abundant on all main Hawaiian islands except Ni‘ihau. Today, the largest known breeding colonies are found at Haleakala Crater on Maui and on the summit of Lana‘i. Other colonies are on Kaua‘i, the island of Hawai‘i, and possibly Moloka‘i.

Threats to this endangered seabird include predation by introduced mammals, development, light attraxtion and collision, ocean pollution, and disturbance of their breeding grounds. The petrel does not have any natural defenses against predators such as rats, feral cats, and mongooses, and their burrows are very vulnerable.

Conservation Efforts:
The U.S. Fish and Wildlife Service, the Hawai‘i Division of Forestry and Wildlife, and the National Park Service work cooperatively to save the ‘ua‘u, by protecting their breeding habitats and controlling predators within Haleakala National Park. The ‘ua‘u was listed as an endangered species on March 11, 1967.

Last updated: November 7, 2008


Last updated: September 20, 2012
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