New insights into prime Southern Ocean forage grounds for thriving Western Australian humpback whales

Abstract Humpback whale populations migrate extensively between winter breeding grounds and summer feeding grounds, however known links to remote Antarctic feeding grounds remain limited in many cases. New satellite tracks detail humpback whale migration pathways from Western Australia into the Sout...

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Bibliographic Details
Published in:Scientific Reports
Main Authors: Bestley, Sophie, Andrews-Goff, Virginia, van Wijk, Esmee, Rintoul, Stephen R., Double, Michael C., How, Jason
Other Authors: Department of Education and Training | Australian Research Council, Fisheries Research and Development Corporation
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science and Business Media LLC 2019
Subjects:
Online Access:http://dx.doi.org/10.1038/s41598-019-50497-2
http://www.nature.com/articles/s41598-019-50497-2.pdf
http://www.nature.com/articles/s41598-019-50497-2
Description
Summary:Abstract Humpback whale populations migrate extensively between winter breeding grounds and summer feeding grounds, however known links to remote Antarctic feeding grounds remain limited in many cases. New satellite tracks detail humpback whale migration pathways from Western Australia into the Southern Ocean. These highlight a focal feeding area during austral spring and early summer at the southern Kerguelen plateau, in a western boundary current where a sharp northward turn and retroflection of ocean fronts occurs along the eastern plateau edge. The topographic steering of oceanographic features here likely supports a predictable, productive and persistent forage ground. The spatial distribution of whaling catches and Discovery era mark-recaptures confirms the importance of this region to Western Australian humpback whales since at least historical times. Movement modelling discriminates sex-related behaviours, with females moving faster during both transit and resident periods, which may be a consequence of size or indicate differential energetic requirements. Relatively short and directed migratory pathways overall, together with high-quality, reliable forage resources may provide a partial explanation for the ongoing strong recovery demonstrated by this population. The combination of new oceanographic information and movement data provides enhanced understanding of important biological processes, which are relevant within the context of the current spatial management and conservation efforts in the Southern Ocean.