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Differences in foraging strategy and maternal behaviour between two sympatric fur seal species at the Crozet Islands

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posted on 2005-06-02, 00:00 authored by F Bailleul, S Luque, L Dubroca, John ArnouldJohn Arnould, C Guinet
Marine top-predators such as marine mammals forage in a heterogeneous environment according to their energetic requirements and to the variation in environmental characteristics. In this study, the behaviour of breeding females in 2 sympatric fur seal species, Antarctic fur seal Arctocephalus gazella and Subantarctic fur seal A. tropicalis, was investigated in relation to foraging effort. Foraging effort was hypothesised to be greater in Antarctic fur seal than in Subantarctic fur seal due to their shorter lactation period. Using satellite telemetry, time-depth recorders and satellite images of sea-surface temperature and chlorophyll a concentration, the foraging grounds, the at-sea activity budgets and the environmental features were determined for both species breeding on the Crozet Archipelago. Foraging cycle duration was similar for the 2 species, and the seals exhibited similar at-sea activity budgets. Only the proportion of time spent at sea was higher in Antarctic fur seals. Separate foraging areas were identified for the 2 species. Antarctic fur seal distribution was related to bathymetric features, while we did not find any direct relationship between chlorophyll a concentration and seal foraging areas. Our results suggest that Antarctic fur seals tend to respond to the higher needs of their pups by having a higher foraging efficiency and concentrating their foraging activity in the most productive areas.

History

Journal

Marine ecolgy progress series

Volume

293

Pagination

273 - 282

Publisher

Inter-Research

Location

Oldendorf, Germany

ISSN

0171-8630

eISSN

1616-1599

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2005, Inter-Research