A large seabird with very long, narrow wings; much larger than shearwaters and petrels. Often confiding and unafraid of humans. Nests on the ground in coastal areas of Kauai and northern Oahu. Abundant in the Northwestern Hawaiian Islands during the breeding season. Nonbreeding birds may visit other islands. Frequently seen offshore from boats and occasionally from shore. Calls include whinnying, low cow-like “moo,” soft grunts, and squeals. Also claps bill.