Hawaiian Petrel

The Hawaiian petrel, or 'ua'u, is a majestic seabird with a striking dark grey-brown and white plumage. This large petrel is an endemic species to the Hawaiian archipelago, a true native of these remote Pacific islands.

Identification Tips

When observing the Hawaiian petrel, look for its long and narrow wings, which span about 36 inches (91 cm), aiding in its characteristic high, steeply banked arcs and glides. The wings and tail exhibit a sooty coloration, while the feet present a unique bicolored pink and black appearance. At night, one may hear its distinctive moaning "oo-ah-oo" calls as it returns to its nest.

Habitat

The Hawaiian petrel has a preference for nesting in burrows or rock crevices, which are typically found in the high-altitude regions of the Hawaiian Islands.

Distribution

Once widespread across the main Hawaiian Islands, the Hawaiian petrel's presence has now contracted. It is primarily found within Haleakalā crater on Maui, with smaller populations on Mauna Loa on Hawai'i, Waimea Canyon on Kaua'i, Lāna'ihale on Lāna'i, and potentially Moloka'i. Sightings have been reported as far afield as the Galapagos Islands, Arizona, Oregon, and California.

Behaviour

The Hawaiian petrel is known for its extensive foraging trips, which can take it as far as Alaska and Japan during the breeding season. These birds are nocturnal feeders, regurgitating food to their chicks after day-long trips to the sea.

Song & Calls

The 'ua'u communicates with a variety of sounds, including yaps, barks, and squeals. Its most notable call is the moaning "oo-ah-oo" heard when adults return to their nesting burrows at night.

Breeding

Breeding season for the Hawaiian petrel extends from March to October. They lay a single white egg in their chosen burrow or crevice, and the charcoal-gray colored chicks were historically considered a delicacy by early Hawaiians.

Diet and Feeding

The diet of the Hawaiian petrel is predominantly composed of squid, which makes up 50–75% of its intake. Fish and crustaceans also contribute to its diet in smaller percentages.

Conservation status

The Hawaiian petrel is currently classified as an endangered species. It faces threats from habitat loss due to development, predation by feral cats, small Asian mongooses, and rats, as well as injuries from wires and disorientation caused by city lights. Conservation efforts, particularly in Haleakalā National Park, are focused on reducing the number of feral animals and mitigating other human-induced hazards to protect this and other rare Hawaiian bird species.