Thursday 20 May 2010, 11:30 AM (AAD Theatrette)
Ben Raymond
Australian Antarctic Data Centre
Shearwater foraging in the Southern Ocean: the roles of prey availability and winds
Sooty and short-tailed shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. The analyses show that the Polar Front is an important foraging zone for these birds during the breeding season. Shearwaters from all three regions foraged here, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters.
