 Like all procellariids the Bonin petrel has a modified area of the gut known as a proventriculus which partly digests prey to create stomach oil, an energy rich oil which is lighter to carry than prey.The Bonin petrel breeds in dense colonies, on islands in the Northwestern Hawaiian Islands; French Frigate Shoals, Laysan, Lisianski Island, Pearl and Hermes Reef, Midway Atoll and Kure Atoll; and on the Volcano Islands and Bonin Islands south of Japan.Colonies are only visited by birds at night, with birds usually arriving soon after sunset.