Baleen whales are not important as prey for killer whales Orcinus orca in high-latitude regions

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 348:297-307 (2007) - DOI: https://doi.org/10.3354/meps07015 Baleen whales are not important as prey for killer whales Orcinus orca in high-latitude regions Amee V. Mehta1,*, Judith M. Allen2, Rochelle Constantine3, Claire Garrigue4, Beatrice Jann5, Curt Jenner6, Marilyn K. Marx7, Craig O. Matkin8, David K. Mattila9, Gianna Minton10, Sally A. Mizroch11, Carlos Olavarría12,17, Jooke Robbins13, Kirsty G. Russell3, Rosemary E. Seton2, Gretchen H. Steiger, 14Gísli A. Víkingsson15, Paul R. Wade11, Briana H. Witteveen16, Phillip J. Clapham11,17 1Boston University Marine Program, 7 MBL Street, Woods Hole, Massachusetts 02543, USA 2Allied Whale, College of the Atlantic, 105 Eden Street, Bar Harbor, Maine 04609, USA 3School of Biological Sciences, Private Bag 92019, University of Auckland, Auckland, New Zealand 4Opération Cétacés, BP12827, Noumea 98802, New Caledonia 5Swiss Whale Society, Via Nolgio 3, 6900 Massagno, Switzerland 6Centre for Whale Research, PO Box 1622, Fremantle, Western Australia 6959, Australia 7New England Aquarium, Central Wharf, Boston, Massachusetts 02110, USA 8North Gulf Oceanic Society, 3430 Main Street, Suite B1, Homer, Alaska 99603, USA 9Hawaiian Islands Humpback Whale National Marine Sanctuary, 726 South Kihei Road, Kihei, Hawaii 96753, USA 10Oman Whale and Dolphin Research Group, PO Box 81, Muscat, Oman 11National Marine Mammal Lab, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, Washington 98115, USA 12Centro de Estudios del Cuaternario (CEQUA), Plaza Muñoz Gamero 1055, Punta Arenas, Chile 13Center for Coastal Studies, PO Box 1036, Provincetown, Massachusetts 02657, USA 14Cascadia Research, 218½ W. 4th Avenue, Olympia, Washington 98501, USA 15Marine Research Institute, Skúlagata 4, PO Box 1390, 121 Reykjavík, Iceland 16University of Alaska Fairbanks, 118 Trident Way, Kodiak, Alaska 99615, USA 17South Pacific Whale Research Consortium, Box 3069, Avarua, Rarotonga, Cook Islands *Email: ameevm@gmail.com ABSTRACT: Certain populations of killer whales Orcinus orca feed primarily or exclusively on marine mammals. However, whether or not baleen whales represent an important prey source for killer whales is debatable. A hypothesis by Springer et al. (2003) suggested that overexploitation of large whales by industrial whaling forced killer whales to prey-switch from baleen whales to pinnipeds and sea otters, resulting in population declines for these smaller marine mammals in the North Pacific and southern Bering Sea. This prey-switching hypothesis is in part contingent upon the idea that killer whales commonly attack mysticetes while they are in these high-latitude areas. In this study, we used photographic and sighting data from long-term studies of baleen whales in 24 regions worldwide to determine the proportion of whales that bear scars (rake marks) from killer whale attacks, and to examine the timing of scar acquisition. The results of this study show that there is considerable geographic variation in the proportion of whales with rake marks, ranging from 0% to >40% in different regions. In every region, the great majority of the scars seen were present on the whales’ bodies when the animals were first sighted. Less than 7% (9 of 132) of scarred humpback whales with multi-year sighting histories acquired new scars after the first sighting. This suggests that most killer whale attacks on baleen whales target young animals, probably calves on their first migration from low-latitude breeding and calving areas to high-latitude feeding grounds. Overall, our results imply that adult baleen whales are not an important prey source for killer whales in high latitudes, and therefore that one of the primary assumptions underlying the Springer et al. (2003) prey-switching hypothesis (and its purported link to industrial whaling) is invalid. KEY WORDS: Predation · Killer whale · Baleen whale · Scars · North Pacific · Whaling Full text in pdf format PreviousCite this article as: Mehta AV, Allen JM, Constantine R, Garrigue C and others (2007) Baleen whales are not important as prey for killer whales Orcinus orca in high-latitude regions. Mar Ecol Prog Ser 348:297-307. https://doi.org/10.3354/meps07015Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 348. Online publication date: October 25, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.