Because of its vocalizations (loud groans, moans and wails), which primarily occur at night in breeding colonies, the Wedge-tailed Shearwater is sometimes referred to as the "moaning bird". Wedge-tailed Shearwaters feed during the day; either individually or in mixed-species flocks. Prey consists of larval forms of goat fish, mackerel scad, and squid driven to the surface by predatory fish.
Dark brown to brownish-gray upperparts. White underparts. Dark wing margins and undertail coverts. Long, thin, slate-grey hooked bill. Wedge-shaped tail. Flesh colored legs and feet. Sexes similar. 16 to 18 inches in length.
Pelagic, only comes ashore to breed.
1 large, white egg. The egg has an average 53 day incubation period. Fledging occurs in 100-115 days. Both parents incubate the egg in shifts that last up to 12 days. The egg is laid in a shallow ground burrow that is one to two meters in length. The parents usually sit head to head near the burrow entrance. The birds are monogamous and return to the same nest site each year. Breeds in colonies.
- Kilauea Point Lighthouse, Kauaui, Hawaii