Don’t mind if I do : Arctic humpback whales respond to winter foraging opportunities before migration
Abstract
Migration patterns are fundamentally linked to the spatio-temporal distributions of prey. How migrating animals can respond to changes in their prey's distribution and abundance remains largely unclear. During the last decade, humpback whales (Megaptera novaeangliae) used specific winter foraging sites in fjords of northern Norway, outside of their main summer foraging season, to feed on herring that started overwintering in the area. We used photographic matching to show that whales sighted during summer in the Barents Sea foraged in northern Norway from late October to February, staying up to three months and showing high inter-annual return rates (up to 82%). The number of identified whales in northern Norway totalled 866 individuals by 2019. Genetic sexing and hormone profiling in both areas demonstrate a female bias in northern Norway and suggest higher proportions of pregnancy in northern Norway. This may indicate that the fjord-based winter feeding is important for pregnant females before migration. Our results suggest that humpback whales can respond to foraging opportunities along their migration pathways, in some cases by continuing their feeding season well into winter. This provides an important reminder to implement dynamic ecosystem management that can account for changes in the spatio-temporal distribution of migrating marine mammals.
Citation
Kettemer , L E , Ramm , T , Broms , F , Biuw , M , Blanchet , M-A , Bourgeon , S , Dubourg , P , Ellendersen , A C J , Horaud , M , Kershaw , J , Miller , P J O , Øien , N , Pallin , L J & Rikardsen , A H 2023 , ' Don’t mind if I do : Arctic humpback whales respond to winter foraging opportunities before migration ' , Royal Society Open Science , vol. 10 , no. 9 . https://doi.org/10.1098/rsos.230069
Publication
Royal Society Open Science
Status
Peer reviewed
ISSN
2054-5703Type
Journal article
Rights
Copyright © 2023 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Description
The project was supported by the ‘Whalefeast project’ (financed by The Regional Research Council in Troms), and the UiT—The Arctic University of Norway and the Institute for Marine Research in Bergen.Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.