The 'ua'u belongs to the expansive Procellariidae family, which encompasses over 50 species of petrels. These seabirds can be found across all of the world's oceans and nearly all of its seas.
Like its seafaring cousins, our Hawaiian petrel spends nearly all of its time on the open water. But between March and November, 'ua'u will return to the highest peaks on the Hawaiian islands, such as Haleakalā on Maui, in order to breed and raise their fledglings.