This shearwater is 43-51 cm in length with a 105-122 cm wingspan. It is identifiable by its size, dark upperparts, and underparts white except for a brown belly patch and dark shoulder markings. It has a black cap, black bill, and a white `horseshoe` on the base of the tail. The stiff flight, like a large Manx Shearwater, is also distinctive. The only other large shearwater in its range is the all-dark Sooty Shearwater.
Habitat and Distribution
This species breeds on Nightingale Island, Inaccessible Island, Tristan da Cunha, and Gough Island. It is one of only a few bird species to migrate from breeding grounds in the Southern Hemisphere to the Northern Hemisphere, the normal pattern being the other way round.
The Great Shearwater feeds on fish and squid, which it catches from the surface or by plunge-diving. It readily follows fishing boats, where it indulges in noisy squabbles.
This shearwater nests in large colonies, laying one white egg in a small burrow or in the open grass. These nests are visited only at night to avoid predation by large gulls.
Calls and Songs
They have a piercing eeyah cry usually given when resting in groups on the water.