Spatial and temporal occurrence of killer whale ecotypes off the outer coast of Washington State, USA

Rice, Ally, Deecke, Volker B., Ford, John K.B., Pilkington, James F., Oleson, Erin M., Hildebrand, John A. and Sirovic, Ana (2017) Spatial and temporal occurrence of killer whale ecotypes off the outer coast of Washington State, USA. Marine Ecology Progress Series, 572 . pp. 255-268. Item availability may be restricted.

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Official URL: https://doi.org/10.3354/meps12158

Abstract

Three killer whale Orcinus orca ecotypes inhabit the northeastern Pacific: residents, transients, and offshores. To investigate intraspecific differences in spatial and temporal occur-rence off the outer coast of Washington State, USA, 2 long-term acoustic recorders were deployed from July 2004 to August 2013: one off the continental shelf in Quinault Canyon (QC) and the other on the shelf, off Cape Elizabeth (CE). Acoustic encounters containing pulsed calls were analyzed for call types attributable to specific ecotypes, as no calls are shared between ecotypes. Both sites showed killer whale presence year-round, although site CE had a higher number of days with en- counters overall. Transients were the most common ecotype at both sites and were encountered mainly during the spring and early summer. Residents were encountered primarily at site CE and showed potential seasonal segregation between the 2 resident communities, with northern resi- dents present mainly during summer and early fall when southern residents were not encountered. Offshore encounters were higher at site QC, with little evidence for seasonality. Spatial and temporal variability of residents and transients matches the distribution of their prey and can potentially be used for further inferences about prey preferences for different transient groups.

Item Type: Article
Journal or Publication Title: Marine Ecology Progress Series
Publisher: Inter Research
ISSN: 1616-1599
Departments: Centre for Wildlife Conservation
Faculty of Health and Science > Science, Natural Resources and Outdoor Studies > Forestry, Conservation & Applied Science
Additional Information: Open Access under Creative Commons by Attribution Licence.
Depositing User: Volker B. Deecke
Date Deposited: 01 Jun 2017 09:52
Last Modified: 17 Nov 2017 16:25
URI: http://insight.cumbria.ac.uk/id/eprint/2985

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