Title Observations of distinctive morphotype of killer whale (Orcinus orca), type D, from subantarctic waters
Author Pitman, R.L.; Durban, J.W.; Greenfelder, M.; Guinet, C.; Jorgensen, M.; Olson, P.A.; Plana, J.; Tixier, P.; Towers, J.R.
Author Affil Pitman, R.L., NOAA, National Marine Fisheiries Service, La Jolla, CA. Other: CNRS, CEBC, France; Quaternary Research Center, Chile; Marine Education and Research Society, Canada
Source Polar Biology, 34(2), p.303-306. Publisher: Springer-Verlag, Berlin, Germany. ISSN: 0722-4060
Publication Date Feb. 2011
Notes In English. 15 refs. GeoRef Acc. No: 308817
Index Terms Southern Ocean; behavior; Cetacea; Chordata; diet; ecology; Eutheria; feeding; Mammalia; physiology; predation; subantarctic regions; Tetrapoda; Theria; Vertebrata
Abstract Studies have shown that killer whale (Orcinus orca) communities in high latitudes regularly comprise assemblages of sympatric "ecotypes"--forms that differ in morphology, behavior, and prey preferences. Although they can appear superficially similar, recent genetic evidence suggests that breeding is assortative among ecotypes within individual communities, and species-level divergences are inferred in some cases. Here, we provide information on a recently recognized "type D" killer whale based on photographs of a 1955 mass stranding in New Zealand and our own six at-sea sightings since 2004. It is the most distinctive-looking form of killer whale that we know of, immediately recognizable by its extremely small white eye patch. Its geographic range appears to be circumglobal in subantarctic waters between latitudes 40S and 60S. School sizes are relatively large (mean 17.6; range 9-35; n=7), and although nothing is known about the type D diet, it is suspected to include fish because groups have been photographed around longline vessels where they reportedly depredate Patagonian toothfish (Dissostichus eleginoides).
URL http://hdl.handle.net/10.1007/s00300-010-0871-3
Publication Type journal article
Record ID 91261