Sooty shearwater
The sooty shearwater (Ardenna griseus) is a medium-large shearwater in the seabird family Procellariidae. In New Zealand it is also known by its Māori name tītī and as muttonbird, like its relatives the wedge-tailed shearwater (A. pacificus) and the Australian short-tailed shearwater (A. tenuirostris).
It appears to be particularly closely related to the great shearwater (A. gravis) and the short-tailed shearwater, all blunt-tailed, black-billed species, but its precise relationships are obscure. In any case, these three species are among the larger species of shearwater that have been moved into a separate genus Ardenna based on a phylogenetic analysis of mitochondrial DNA.
Description
Sooty shearwaters are 40–51 cm in length with a 94–110 cm wingspan. It has the typical "shearing" flight of the genus, dipping from side to side on stiff wings with few wing beats, the wingtips almost touching the water. Its flight is powerful and direct, with wings held stiff and straight, giving the impression of a very small albatross. This shearwater is identifiable by its dark plumage, which is responsible for its name. In poor viewing conditions, it looks all black, but in good light, it shows as dark chocolate-brown a silvery strip along the center of the underwing.
