Library Open Repository

Blubber fatty acid profiles indicate dietary resource partitioning juvenile southern between adult and elephant seals

Downloads

Downloads per month over past year

Newland, C and Field, IC and Nichols, PD and Bradshaw, CJA and Hindell, MA (2009) Blubber fatty acid profiles indicate dietary resource partitioning juvenile southern between adult and elephant seals. Marine Ecology Progress Series, 384. pp. 303-312. ISSN Print 0171-8630 Online 1616-1599

[img]
Preview
PDF
Blubber_fatty_acid_profiles...pdf | Download (137kB)
Available under University of Tasmania Standard License.

Abstract

When resources are limited or patchy, a species may develop some degree of resource partitioning to reduce intra-specific competition. Development of intra-specific resource partitioning is more pronounced in species with clear phenotypic variation among individuals (e.g. age or sex). Southern elephant seals Mirounga leonina have pronounced sexual dimorphism and range widely in size and foraging range between juvenile and adult stages. However, hypothesized diet-based resource partitioning has been less clear due to difficulties in sampling diet while seals are away from breeding islands. We analysed fatty acids (FAs) from blubber of 122 juvenile seals and compared them to FA profiles from blubber of 52 adult females, and to FA profiles from 51 prey species (grouped as fish and squid) to examine evidence for diet-based resource partitioning in the seals. FA signature analysis revealed physiological and dietary differences between ages. Principle components of the 21 FAs from seal blubber and prey parts distinguished prey from seals, and clearly separated prey species into fish and squid classes. FA profiles from adult females differed to those from juveniles, with the former more 'squid-like' and the latter more 'fish-like'. Variation in FA profiles of seals was also apparent between sexes and during different seasons. Differences in diet between juveniles and adult females suggest resource partitioning occurs in response to large metabolic and physiological differences with age that limit juvenile dispersal and diving abilities. By consuming a different suite of prey species relative to adult females, juvenile southern elephant seals may reduce intra-specific competition.

Item Type: Article
Keywords: Fatty acid signature analysis · Southern elephant seal · Diet · Resource partitioning
Journal or Publication Title: Marine Ecology Progress Series
Page Range: pp. 303-312
ISSN: Print 0171-8630 Online 1616-1599
Identification Number - DOI: 10.3354/meps08010
Additional Information: © 2009 Inter-Research
Date Deposited: 21 Sep 2009 01:14
Last Modified: 18 Nov 2014 04:05
URI: http://eprints.utas.edu.au/id/eprint/9227
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page