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dc.contributor.supervisor Ferguson, Steven (Biological Sciences) en_US
dc.contributor.author Matthews, Cory
dc.date.accessioned 2015-01-06T20:48:45Z
dc.date.available 2015-01-06T20:48:45Z
dc.date.issued 2013-09-11 en_US
dc.identifier.citation Matthews, C.J.D. and Ferguson, S.H. Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis. Journal of the Marine Biological Association of the United Kingdom. doi:10.1017/S0025315413001379. en_US
dc.identifier.uri http://hdl.handle.net/1993/30149
dc.description.abstract An animal’s foraging ecology can vary over a range of temporal scales, mirroring seasonal and longer term changes in prey availability, as well as ontogenetic shifts in diet and distribution. Obtaining individual-based, longitudinal diet information through direct observation, however, is logistically challenging for marine mammals that pursue and consume prey underwater, and are often widely distributed. Isotopic profiling along continuously growing tissues like teeth and baleen, which archive dietary inputs at the time of growth in their stable isotope composition, allows for chronological dietary reconstructions over multi-year timespans. This thesis reports longitudinal diet studies of three Arctic whale species, killer whales (Orcinus orca), bowhead whales (Balaena mysticetus) and beluga whales (Delphinapterus leucas), derived from serial isotopic measurements along teeth and baleen. Study objectives varied by species, but general goals were to characterize seasonal, ontogenetic, and/or individual diet variation. Results revealed similar trophic-level diet, but regional spatial separation, among eastern Canadian Arctic/Northwest Atlantic killer whales. However, isotope and tooth wear differences between two individuals and the rest of the sampled whales suggested potential specialisation on sharks, while the other whales likely had diets comprising marine mammals. Cyclic isotopic variation along Eastern Canada-West Greenland bowhead whale baleen was consistent with year-round foraging, although at a reduced rate during winter. Resting zooplankton could be an important food resource outside of periods of peak productivity, and accessibility likely drives winter habitat selection. Isotopic cycling did not differ between female and male bowheads, or among age classes, indicating similar seasonal foraging patterns despite reported spatial segregation throughout their summer range. Individual beluga whales from three eastern Canadian Arctic populations varied in timing of ontogenetic diet shifts (i.e. weaning age), as well as overall trophic position, which could reflect size-specific energetic requirements and foraging capabilities. Population-specific beluga whale diet trends over a period of several decades likely reflected climate-related expansions of southern forage fish. Collectively, findings of seasonal, ontogenetic, and/or individual diet variation contribute a greater understanding of intrapopulation variation in foraging ecology of these species, and of large-scale structuring of Arctic marine ecosystems. en_US
dc.publisher Marine Biological Association of the United Kingdom en_US
dc.subject Orcinus orca en_US
dc.subject Delphinapterus leucas en_US
dc.subject Balaena mysticetus en_US
dc.subject killer whale en_US
dc.subject bowhead whale en_US
dc.subject beluga whale en_US
dc.subject diet en_US
dc.subject distribution en_US
dc.subject niche partitioning en_US
dc.subject weaning en_US
dc.subject specialisation en_US
dc.subject stable isotopes en_US
dc.subject time series en_US
dc.title Longitudinal Diet Studies of Arctic Whales en_US
dc.degree.discipline Biological Sciences en_US
dc.contributor.examiningcommittee Davoren, Gail (Biological Sciences) Halden, Norman (Geological Sciences) McGloughlin, Philip (Biology, University of Saskatoon) en_US
dc.degree.level Doctor of Philosophy (Ph.D.) en_US
dc.description.note February 2015 en_US


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