Breeding tropical shearwaters use distant foraging sites when self-provisioning

To determine whether breeding tropical shearwaters use “at-distance” locations during the long-trip phase of their bimodal foraging cycle, we deployed PTT satellite tracking devices on adult Wedge-tailed Shearwaters Ardenna pacifica of the Great Barrier Reef (GBR), Australia, over three breeding seasons. During the long-trip phase (8–14 d), a component of a bimodal pattern of foraging not seen previously in a tropical shearwater, birds travelled to distant sites in the Coral Sea between 300 and 1 100 km from the breeding colony, primarily to the north and east. At-distance foraging sites were in deeper water and closer to seamounts than were near-colony foraging sites used for chick provisioning, a combination of features indicating enhanced prey availability at these at-distance locations. These findings imply that longterm reproductive success at this and likely other GBR colonies is strongly dependent on the continued stability of these at-distance locations, yet at present all are outside the current Great Barrier Reef Marine Park management zone. To adequately conserve GBR seabirds and other marine species using these resources, a conservation strategy integrated with current management practices is needed for the open waters of the Coral Sea.