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| Bigg’s killer whale Orcinus rectipinnus (Cope in Scammon, 1869) Resident killer whale Orcinus ater (Cope in Scammon, 1869) in Morin, McCarthy Fung, Durban, Parsons, Perrin, Taylor, Jefferson & Archer, 2024. DOI: 10.1098/rsos.231368 |
Abstract
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).
Keywords: Cetacea, odontocete, speciation
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| Vertical images of (a) an adult male Bigg’s killer whale (BKW) from the West Coast Transient population of Bigg’s killer whales and (b) an adult male resident killer whale (RKW) from the sympatric Southern Resident population of resident killer whales. Images are scaled to the estimated asymptotic lengths of 7.3 m and 6.9 m, respectively. Vertical images were collected using an octocopter drone using methods described by Durban et al. [2022], provided by John Durban and Holly Fearnbach. |
Order Artiodactyla Montgelard, Catzefils and Douzery, 1997
Cetacea Brisson, 1762
Odontoceti Flower, 1867
Superfamily Delphinoidea Flower, 1865
Family Delphinidae Gray, 1821
Orcinus rectipinnus (Cope in Scammon, 1869)
Etymology: In Latin, recti means right or upright, and pinna means fin, feather or wing, most likely referring to the tall, erect dorsal fin of males.
Synonymy: Orca rectipinna Cope in Scammon, 1869: 22; original designation.
Common name: We propose continued use of the common name, ‘Bigg’s killer whale’, for this species, to honour Dr. Michael A. Bigg (1939–1990), who pioneered the study of North Pacific killer whales in the 1970s. This ecotype was formerly known as the ‘transient killer whale’.
Orcinus ater (Cope in Scammon, 1869)
Etymology: In Latin, ater means black or dark, which probably refers to the largely black colour of this species.
Synonymy: Orca ater Cope in Scammon, 1869: 22; original designation.
Common name: We are planning on engaging with North American Indigenous tribal groups and expect to eventually have a consensus common name, but in the meantime, we suggest continued use of ‘resident killer whale’ so as to maintain consistency.
Phillip A. Morin, Morgan L. McCarthy Charissa W. Fung, John W. Durban, Kim M. Parsons, William F. Perrin, Barbara L. Taylor, Thomas A. Jefferson and Frederick I. Archer. 2024. Revised Taxonomy of eastern North Pacific Killer Whales (Orcinus orca): Bigg’s and Resident Ecotypes deserve Species Status. R. Soc. Open Sci. 11: 231368. DOI: 10.1098/rsos.231368
