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.
Galápagos shearwater Galápagos shearwater The Galápagos shearwater ("Puffinus subalaris") is a small shearwater. Until recently it was considered to be a subspecies of Audubon's shearwater, but it is actually one of two members of a very ancient lineage of the small "Puffinus" species, the other being, as indicated by mtDNA cytochrome "b" sequence data, the Christmas shearwater. It is an endemic breeder of the Galápagos Islands, and is largely sedentary, although individuals are commonly seen as far as the Oaxacan coast of Mexico. The Galápagos shearwater has dark brown upperparts, undertail and underwing flight feathers, the rest of the underparts plumage being