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.
San Benedicto Island location where several seabirds of the tropical Eastern Pacific come to breed. Taxa breeding on San Benedicto are: The nearly extinct Townsend's shearwater ("Puffinus auricularis") does not seem to breed on San Benedicto, but can sometimes be seen feeding offshore. Given that there are no invasive species on San Benedicto and also no predators apart from the frigatebirds, the island might be highly suitable for establishing a new colony. Indeed, it bred here before the 1952 eruption; shearwaters are highly conservative in choosing their breeding locations, which explains why San Benedicto has not yet been recolonized. Vagrants of other species,