Newell's shearwater donkey-like braying call around the breeding areas. Townsend's shearwater ("P. auricularis") is very similar but has dark undertail-coverts, a shorter tail and a less sharp boundary between the black and white on the face. It was described as a new species "Puffinus newelli" in 1900 by the American ornithologist Henry Wetherbee Henshaw using specimens obtained by Brother Matthias Newell from residents of Maui. It was later included by some authors in the Manx shearwater ("Puffinus puffinus") as was Townsend's shearwater ("Puffinus auricularis"). Later, Townsends's shearwater was raised back to species status with Newell's shearwater as a subspecies of it. This
Procellariidae with "Pseudobulweria" being phylogenetically closer to the "Puffinus" shearwaters than the "Pterodroma" gadfly petrels, and "Aphrodroma" (the Kerguelen petrel) possibly being closely related to the shearwaters or the fulmars. The prions, according to Nunn and Stanley, were among the larger shearwater group. The "Calonectris" shearwaters were placed close to the two "Puffinus" clades (closer to the Puffinus, or small, clade) and both were distant to the "Procellaria" shearwaters. The relationships between the genera and within the genera are still the subject of debate, with researchers lumping and splitting the species and genera within the family and arguing about the position