Drivers and consequences of apex predator diet composition in the Canadian Beaufort Sea

dc.contributor.authorFlorko, Katie
dc.contributor.authorThiemann, Gregory W.
dc.contributor.authorBromaghin, J. F.
dc.date.accessioned2021-11-23T01:12:02Z
dc.date.available2021-11-23T01:12:02Z
dc.date.issued2020-09-08
dc.description.abstractPolar bears (Ursus maritimus) rely on annual sea ice as their primary habitat for hunting marine mammal prey. Given their long lifespan, wide geographic distribution, and position at the top of the Arctic marine food web, the diet composition of polar bears can provide insights into temporal and spatial ecosystem dynamics related to climate-mediated sea ice loss. Polar bears with the greatest ecological constraints on diet composition may be most vulnerable to climate-related changes in ice conditions and prey availability. We used quantitative fatty acid signature analysis (QFASA) to estimate the diets of polar bears (n = 419) in two western Canadian Arctic subpopulations (Northern Beaufort Sea and Southern Beaufort Sea) from 1999 to 2015. Polar bear diets were dominated by ringed seal (Pusa hispida), with interannual, seasonal, age- and sex-specific variation. Foraging area and sea ice conditions also affected polar bear diet composition. Most variation in bear diet was explained by longitude, reflecting spatial variation in prey availability. Sea ice conditions (extent, thickness, and seasonal duration) declined throughout the study period, and date of sea ice break-up in the preceding spring was positively correlated with female body condition and consumption of beluga whale (Delphinapterus leucas), suggesting that bears foraged on beluga whales during entrapment events. Female body condition was positively correlated with ringed seal consumption, and negatively correlated with bearded seal consumption. This study provides insights into the complex relationships between declining sea ice habitat and the diet composition and foraging success of a wide-ranging apex predator.en_US
dc.identifier.citationFlorko, K.R.N., Thiemann, G.W. & Bromaghin, J.F. Drivers and consequences of apex predator diet composition in the Canadian Beaufort Sea. Oecologia 194, 51–63 (2020). https://doi.org/10.1007/s00442-020-04747-0en_US
dc.identifier.issn0029-8549
dc.identifier.issn1432-1939
dc.identifier.urihttps://doi.org/10.1007/s00442-020-04747-0en_US
dc.identifier.urihttp://hdl.handle.net/10315/38833
dc.language.isoenen_US
dc.publisherSpringeren_US
dc.rightsThis version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s Accepted Manuscript terms of use (https://www.springernature.com/gp/open-research/policies/accepted-manuscript-terms), but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00442-020-04747-0en_US
dc.subjectForaging ecologyen_US
dc.subjectFatty acidsen_US
dc.subjectSea iceen_US
dc.subjectClimate changeen_US
dc.subjectPolar bearen_US
dc.titleDrivers and consequences of apex predator diet composition in the Canadian Beaufort Seaen_US
dc.typeArticleen_US

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