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Age-related shifts in the diet composition of southern elephant seals expand overall foraging niche
journal contribution
posted on 2023-05-16, 21:18 authored by Field, IC, Bradshaw, CJA, van den Hoff, J, Burton, HR, Mark HindellMark HindellSouthern elephant seals are important apex predators in a highly variable and unpredictable marine environment. In the presence of resource limitation, foraging behaviours evolve to reduce intra-specific competition increasing a species' overall probability of successful foraging. We examined the diet of 141 (aged 1-3 years) juvenile southern elephant seals to test the hypotheses that differences between ages, sexes and seasons in diet structure occur. We described prey species composition for common squid and fish species and the mean size of cephalopod prey items for these age groups. Three cephalopod species dominated the stomach samples, Alluroteuthis antarcticus, Histioteuthis eltaninae and Slosarczykovia circumantarcticus. We found age-related differences in both species composition and size of larger prey species that probably relate to ontogenetic changes in diving ability and haul-out behaviour and prey availability. These changes in foraging behaviour and diet are hypothesised to reduce intra-specific food competition concomitant with the increase in foraging niche of growing juveniles. © 2006 Springer-Verlag.
History
Publication title
Marine BiologyVolume
150Issue
6Pagination
1441-1452ISSN
0025-3162Department/School
School of Natural SciencesPublisher
SpringerPlace of publication
GermanyRepository Status
- Restricted