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Temporal records of diet diversity dynamics in individual adult female Steller sea lion (Eumetopias jubatus) vibrissae.
Doll, A C; Taras, B D; Stricker, C A; Rea, L D; O'Hara, T M; Cyr, A P; McDermott, S; Loomis, T M; Fadely, B S; Wunder, M B.
Affiliation
  • Doll AC; Department of Integrative Biology, University of Colorado-Denver, Denver, CO, USA. acdoll@gmail.com.
  • Taras BD; Alaska Department of Fish and Game, Division of Wildlife Conservation, Fairbanks, AK, USA.
  • Stricker CA; US Geological Survey, Fort Collins Science Center, Denver, CO, USA.
  • Rea LD; Alaska Department of Fish and Game, Division of Wildlife Conservation, Fairbanks, AK, USA.
  • O'Hara TM; Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK, USA.
  • Cyr AP; Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK, USA.
  • McDermott S; College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, USA.
  • Loomis TM; Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA, USA.
  • Fadely BS; Ocean Peace Inc, 13591 Spendlove Drive, Anchorage, AK, USA.
  • Wunder MB; Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA, USA.
Oecologia ; 188(1): 263-275, 2018 Sep.
Article in En | MEDLINE | ID: mdl-29948317
Detailed information on the nutrition of free-ranging mammals contributes to the understanding of life history requirements, yet is often quite limited temporally for most species. Reliable dietary inferences can be made by analyzing the stable carbon (C) and nitrogen (N) isotopic values (δ13C and δ15N) of some consumer tissues; exactly which tissue is utilized dictates the inferential scope. Steller sea lion (SSL) vibrissae are grown continuously without shedding and thus provide a continuous multi-year record of dietary consumption. We applied a novel kernel density approach to compare the δ13C and δ15N values along the length of SSL vibrissae with δ13C and δ15N distributions of potential prey species. This resulted in time-series of proportion estimates of dietary consumption for individual SSL. Substantial overlap in δ13C and δ15N distributions for prey species prevented a discrete species-scale assessment of SSL diets; however, a post hoc correlational analysis of diet proportion estimates revealed grouping by trophic level. Our findings suggest that adult female SSL diets in the western and central Aleutian Islands shift significantly according to season: diets contain a higher proportion of lower trophic level species (Pacific Ocean perch, northern rockfish, Atka mackerel and walleye pollock) in the summer, whereas in the winter SSL consume a much more diverse diet which includes a greater proportion of higher trophic level species (arrowtooth flounder, Kamchatka flounder, darkfin sculpin, Pacific cod, Pacific octopus, rock sole, snailfish, and yellow Irish lord).
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Perciformes / Sea Lions Limits: Animals Country/Region as subject: America do norte Language: En Journal: Oecologia Year: 2018 Document type: Article Affiliation country: Estados Unidos Country of publication: Alemania

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Perciformes / Sea Lions Limits: Animals Country/Region as subject: America do norte Language: En Journal: Oecologia Year: 2018 Document type: Article Affiliation country: Estados Unidos Country of publication: Alemania