Movement and diving of killer whales (Orcinus orca) at a Southern Ocean archipelago

Show simple item record Reisinger, Ryan Rudolf Keith, Mark Andrews, Russel D. De Bruyn, P.J. Nico 2015-09-18T10:18:04Z 2015-12
dc.description.abstract Eleven satellite tagswere deployed on 9 killerwhales at the Prince Edwards Islands in the Southern Ocean. Statespace switchingmodelswere used to generate position estimates fromArgos location data,while two behavioural modes were estimated from the data. Individuals were tracked for 5.6–53.2 days, duringwhich time they moved 416–4470 km (mean 82.7 km day−1) but 69% of position estimates were within the 1000 m depth contour around the islands (b35 km from the tagging site). Killerwhales showed restricted behaviour close to the islands, particularly inshorewhere they can effectively hunt seals and penguins, and at seamounts to the north of the islands. Generalised linear mixed effect models were used to explore the relationship between environmental variables and behavioural mode. The best model included depth, sea surface temperature, latitude, sea surface height anomaly and bottomslope, but killerwhales did not clearly target features such as fronts and apparentmesoscale eddies. Killer whales showed restricted behaviour in shallow water, at high latitudes and low sea surface temperature — the conditions characterising the archipelago. Dive data fromtwo individuals largely revealed shallow dives (7.5–50mdeep), but deeper dive bouts to around 368mwere also recorded. Diveswere significantly deeper during the day and maximumdive depthswere 767.5 and 499.5 m, respectively. This suggests that killer whales might also prey on vertically migrating cephalopods and perhaps Patagonian toothfish. Three individuals made rapid and directed long-distance movements northwards of the islands, the reasons for which are speculative. en_ZA
dc.description.embargo 2016-12-31
dc.description.librarian hb2015 en_ZA
dc.description.sponsorship National Research Foundation’s (NRF) Thuthuka, South African National Antarctic programmes, the South African Department of Science and Technology through the NRF, the Mohamed bin Zayed Species Conservation Fund (Project number: 10251290) and the International Whaling Commission’s Southern Ocean Research Partnership. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Reisinger, RR, Keith, M, Andrews, RD & De Bruyn, PJN 2015, 'Movement and diving of killer whales (Orcinus orca) at a Southern Ocean archipelago', Journal of Experimental Marine Biology and Ecology, vol. 473, no. 90-102. en_ZA
dc.identifier.issn 0022-0981 (print)
dc.identifier.issn 1879-1697 (online)
dc.identifier.other 10.1016/j.jembe.2015.08.008
dc.language.iso en en_ZA
dc.publisher Elsevier en_ZA
dc.rights © 2015 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Experimental Marine Biology and Ecology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Experimental Marine Biology and Ecology, vol. 473, pp. 90-102, 2015. doi :10.1016/j.jembe.2015.08.008. en_ZA
dc.subject Killer whale en_ZA
dc.subject Orcinus orca en_ZA
dc.subject Movement en_ZA
dc.subject Diving en_ZA
dc.subject Tracking en_ZA
dc.subject Satellite tagging en_ZA
dc.title Movement and diving of killer whales (Orcinus orca) at a Southern Ocean archipelago en_ZA
dc.type Postprint Article en_ZA

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