Revised taxonomy of eastern North Pacific killer whales (Orcinus orca): Bigg’s and resident ecotypes deserve species status

Killer whales (Orcinus orca) are currently recognized as a single
ecologically and morphologically diverse, globally-distributed species.
Multiple morphotypes or ecotypes have been described, often associated
with feeding specialization, and several studies have suggested taxonomic
revision to include multiple subspecies or species in the genus. We review
the ecological, morphological and genetic data for the well-studied
“resident” and Bigg’s (aka “transient”) ecotypes in the eastern North
Pacific, and use quantitative taxonomic guidelines and standards to
determine whether the taxonomic status of these killer whale ecotypes
should be revised. Our review and new analyses indicate that species-level
status is justified in both cases, and we conclude that eastern North
Pacific Bigg’s killer whales should be recognized as Orcinus rectipinnus
(Cope in Scammon, 1869), and resident killer whales should be recognized
as Orcinus ater (Cope in Scammon, 1869).