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Age-related shifts in the diet composition of southern elephant seals expand overall foraging niche


Field, IC and Bradshaw, CJA and van den Hoff, J and Burton, HR and Hindell, MA, Age-related shifts in the diet composition of southern elephant seals expand overall foraging niche, Marine Biology, 150, (6) pp. 1441-1452. ISSN 0025-3162 (2007) [Refereed Article]

DOI: doi:10.1007/s00227-006-0417-y


Southern 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.

Item Details

Item Type:Refereed Article
Research Division:Environmental Sciences
Research Group:Environmental management
Research Field:Wildlife and habitat management
Objective Division:Environmental Management
Objective Group:Coastal and estuarine systems and management
Objective Field:Assessment and management of coastal and estuarine ecosystems
UTAS Author:Field, IC (Dr Iain Field)
UTAS Author:Bradshaw, CJA (Dr Corey Bradshaw)
UTAS Author:Hindell, MA (Professor Mark Hindell)
ID Code:50747
Year Published:2007
Web of Science® Times Cited:56
Deposited By:Zoology
Deposited On:2007-08-01
Last Modified:2008-04-02

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