Animal Diversity Web's broad treatment of Puffinus auricularis includes Newell's shearwater in Hawaii and Townsend's shearwater off Mexico. Some taxonomies split them; ʻAʻo is the Hawaiian name for the Newell's population.
The upperparts are black or sooty brown and the underparts are white, with white patches on the sides. The Hawaiian and Mexican populations also differ in tail length and undertail pattern.
It dives from the sea surface to catch fish and squid, then nests in burrows on island slopes or grassland. Adults visit breeding colonies at night.
An extinction-risk assessment has not been added yet.