title: Killer whale call frequency is similar across the oceans, but varies across sympatric ecotypes.
abstract: Killer whale populations may differ in genetics, morphology, ecology, and behavior. In the North Pacific, two sympatric populations ("resident" and "transient") specialize on different prey (fish and marine mammals) and retain reproductive isolation. In the eastern North Atlantic, whales from the same populations have been observed feeding on both fish and marine mammals. Fish-eating North Pacific "residents" are more genetically related to eastern North Atlantic killer whales than to sympatric mammal-eating "transients." In this paper, a comparison of frequency variables in killer whale calls recorded from four North Pacific resident, two North Pacific transient, and two eastern North Atlantic populations is reported to assess which factors drive the large-scale changes in call structure. Both low-frequency and high-frequency components of North Pacific transient killer whale calls have significantly lower frequencies than those of the North Pacific resident and North Atlantic populations. The difference in frequencies could be related to ecological specialization or to the phylogenetic history of these populations. North Pacific transient killer whales may have genetically inherited predisposition toward lower frequencies that may shape their learned repertoires.
authors.affiliation: Department of Vertebrate Zoology, Faculty of Biology, Moscow State University, Moscow 119991, Russia.
authors.forename: Olga A
authors.initials: OA
authors.lastname: Filatova
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, Scotland.
authors.forename: Patrick J O
authors.initials: PJ
authors.lastname: Miller
authors.affiliation: JASCO Applied Sciences Ltd., 2305-4464 Markham Street, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Harald
authors.initials: H
authors.lastname: Yurk
authors.affiliation: Marine Research Institute, Skulagata 4, Reykjavik 121, Iceland.
authors.forename: Filipa I P
authors.initials: FI
authors.lastname: Samarra
authors.affiliation: Whale and Dolphin Conservation, Park House, Allington Park, Bridport, Dorset DT6 5DD, United Kingdom.
authors.forename: Erich
authors.initials: E
authors.lastname: Hoyt
authors.affiliation: Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia V9T 1K6, Canada.
authors.forename: John K B
authors.initials: JK
authors.lastname: Ford
authors.affiliation: North Gulf Oceanic Society, Homer, Alaska 99603, USA.
authors.forename: Craig O
authors.initials: CO
authors.lastname: Matkin
authors.affiliation: Vancouver Aquarium Marine Science Centre, Vancouver, British Columbia V6B 3X8, Canada.
authors.forename: Lance G
authors.initials: LG
authors.lastname: Barrett-Lennard
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D060146:Ecotype; D005247:Feeding Behavior; D010140:Pacific Ocean; D013016:Sound; D061350:Sympatry / Q000502:physiology*; D014828:Vocalization, Animal; D050685:Whale, Killer / Q000502:physiology*