The "Greater Shearwater" is identifiable by its size. His dark upperparts are designed in a scaly pattern, and there is a white "horseshoe" at the base of the tail. His underparts are white except for a brown belly patch. His bill is black. Among the most widespread seabirds in the world, shearwaters are also some of the deepest diving ones. They pursue their prey underwater with partially open wings and paddling feet.
This bird has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wingbeats, the wingtips almost touching the water. Its flight is powerful and direct, with wings held stiff and straight.
This species breeds on Nightingale Island, Inaccessible Island, Tristan da Cunha and Gough Island in the South Atlantic.
Calls or song.
The "Greater Shearwater" is usually silent at sea, but while resting on the water, utters a low nasal, squealing call.
Population and distribution.
Its habitat the open ocean, the "Greater Shearwater" is one of only a few bird species to migrate from breeding grounds in the Southern Hemisphere to the Northern Hemisphere following the "Great Circle", the normal pattern being the other way round.
The "Greater Shearwater" nests in large colonies, laying one white egg in a small burrow on a grassy slope. These nests are visited only at night to avoid predation by large gulls.