University of Tasmania
Browse

File(s) under permanent embargo

Influence of intrinsic variation on foraging behaviour of adult female Australian fur seals

journal contribution
posted on 2023-05-18, 16:03 authored by Hoskins, AJ, Costa, DP, Wheatley, KE, Gibbens, JR, Arnould, JPY
Phenotypic variation and individual experience can create behavioural and/or dietary variation within a population. This may reduce intra-specific competition, creating a buffer to environmental change. This study examined how intrinsic variation affects foraging behaviour of Australian fur seals. Foraging movements of 29 female Australian fur seals were recorded using FastLoc GPS and dive behaviour recorders. For each individual, body mass, flipper length and axis length were recorded, a tooth was sampled to determine age, and milk was collected for diet analysis. Clustering of fatty acid dietary analysis revealed 5 distinct groups in the population. Behaviour was described using 19 indices, which were then reduced to 7 principal components (>80% of the behavioural variation). Bayesian mixed effect models were developed to describe the relationship between these components and intrinsic variation. No association was found between diet and age or body shape; however, age had a negative relationship with component 1 (27% of variation). Older females spent less time at-sea and foraged nearer to the colony. Age had an effect on component 5 (7% of variation), which represented haul-outs and dive depth; older females made fewer visits to haul-out sites and dived deeper to the benthos. This suggests that as animals age they are able to utilise prior knowledge to exploit nearby foraging sites that younger animals are either unaware of, or have yet to gain the experience required to efficiently utilise. Mass had a negative effect on components representing the directedness of a foraging trip, suggesting heavier individuals were more likely to travel directly to a foraging site.

History

Publication title

Marine Ecology - Progress Series

Volume

526

Pagination

227-239

ISSN

0171-8630

Department/School

School of Natural Sciences

Publisher

Inter-Research

Place of publication

Nordbunte 23, Oldendorf Luhe, Germany, D-21385

Rights statement

Copyright 2015 Inter-Research

Repository Status

  • Restricted

Socio-economic Objectives

Marine biodiversity

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC