Dual-foraging and co-ordinated provisioning in a tropical Procellariiform, the wedge-tailed shearwater

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 301:293-301 (2005) - doi:10.3354/meps301293 Dual-foraging and co-ordinated provisioning in a tropical Procellariiform, the wedge-tailed shearwater Bradley C. Congdon*, Andrew K. Krockenberger, Brian V. Smithers School of Tropical Biology, James Cook University, PO Box 6811, Cairns, Queensland 4870, Australia *Email: brad.congdon@jcu.edu.au ABSTRACT: To sustain breeding while simultaneously compensating for poor local resource availability, many temperate Procellariiformes (tube-nosed seabirds) access highly productive areas ‘at-distance’ from breeding colonies using a unique dual-foraging strategy. We tested for, and observed, a similar dual foraging strategy in a tropical Procellariiform, the wedge-tailed shearwater Puffinus pacificus. Foraging adults repeatedly performed short-trip cycles of multiple 1 to 4 d trips followed by a single long-trip of ~8 d. As with temperate species, wedge-tailed shearwaters used long-trips to build body reserves that they passed onto chicks by not self-provisioning adequately during the early stages of each short-trip cycle. Unlike temperate species (1) long-trip length and adult mass change during long-trips was inversely related to adult mass at the beginning of the same long-trip, and (2) foraging mode changeover appeared to be co-ordinated and was not initiated by adults reaching some critical lower mass. This implies that the dual-foraging pattern observed in wedge-tailed shearwaters is a consequence of the median time adults require to replenish body reserves on long-trips. We conclude that foraging strategies in wedge-tailed shearwaters vary spatially relative to near-colony resource availability, and that dual-foraging is a general Procellariiform life-history strategy used to address similar ecological constraints in both temperate and tropical systems. Our findings suggest that wedge-tailed shearwaters of the southern Great Barrier Reef (GBR) may be dependent on localised areas of high productivity ‘at-distance’ from breeding colonies to sustain breeding. KEY WORDS: Dual-foraging · Co-ordinated provisioning · Feeding ecology · Wedge-tailed shearwater · Puffinus pacificus · Procellariiform · Great Barrier Reef Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 301. Online publication date: October 11, 2005 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2005 Inter-Research.