Audubon's shearwater ill-resolved clade also including such species as the little shearwater, the Manx shearwater ("P. puffinus") or the black-vented shearwater ("P. opisthomelas"). The little-known Heinroth's shearwater ("P. heinrothi") is sometimes considered a subspecies of either Audubon's or the little shearwater. Though it is likely to be another member of that close-knit group, its actual relationships remain uncertain due to lack of specimens. Audubon's shearwater itself has around 10 subspecies. Several have at one time or another been suggested to constitute separate species. For example, the Galápagos Islands population has turned out to be a very distinct species, the Galápagos shearwater ("P.
Shearwater Shearwater Shearwaters are medium-sized long-winged seabirds. There are more than 30 species of shearwaters, a few larger ones in the genus "Calonectris" and many smaller species in the genus "Puffinus". The "Procellaria" petrels and "Bulweria" were believed to belong to this group, but are only distantly related based on more recent studies, while the "Pseudobulweria" and "Lugensa" "petrels" are more closely related. The genus "Puffinus" can be divided into a group of small species close to "Calonectris" and a few larger ones more distantly related to both. These birds are most common in temperate and cold waters. They are pelagic