MEPS 293:273-282 (2005)  -  doi:10.3354/meps293273

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

Frédéric Bailleul1,*, Sebastian Luque1,2, Laurent Dubroca1, John P. Y. Arnould3, Christophe Guinet1

1Centre d’Etudes Biologiques de Chizé, Centre National de la Recherche Scientifique, 79360 Villiers en Bois, France
2Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3X9, Canada
3School of Biological and Chemical Sciences, Deakin University, Burwood 3125, Victoria, Australia

ABSTRACT: 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.


KEY WORDS: Activity budget · Spatial distribution · Environmental features · Otariidea · Arctocephalus gazella · Arctocephalus tropicalis


Full text in pdf format 
Export citation: Endnote - Reference Manager
Mail this link - Contents Mailing Lists - RSS
- -