Southern Ocean humpback whales are shifting to an earlier return migration
Abstract The Southern Ocean ecosystem is undergoing unprecedented environmental changes, which have led to shifts in the primary food source of baleen whales, Antarctic krill. Additionally, many humpback whale populations have rebounded from near extirpation due to historical whaling, increasing pre...
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Nature Portfolio
2025-07-01
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| Series: | Scientific Reports |
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| Online Access: | https://doi.org/10.1038/s41598-025-07010-9 |
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| author | Rebecca Dunlop Emma Gumley Ella Holding McGrath Michael Noad |
| author_facet | Rebecca Dunlop Emma Gumley Ella Holding McGrath Michael Noad |
| author_sort | Rebecca Dunlop |
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| description | Abstract The Southern Ocean ecosystem is undergoing unprecedented environmental changes, which have led to shifts in the primary food source of baleen whales, Antarctic krill. Additionally, many humpback whale populations have rebounded from near extirpation due to historical whaling, increasing pressure on now vulnerable krill populations. Since humpback whales rely on energy reserves built up during their feeding season to sustain them during migration, changes in their food supply are likely to influence their migration strategies. In this study, the timing of the ‘return to feeding grounds,’ or southern migration, of the eastern Australian humpback whale population was tracked over a 21-year period. Both land-based and acoustic surveys were used to estimate the timing of the migratory peak in southern Queensland, i.e., the week with the highest number of whales sighted or recorded. Land-based surveys recorded all whales, including females with newborn calves, while acoustic surveys recorded singing adult males. Both datasets revealed that the peak of the southern migration has shifted earlier by approximately three weeks from 2003 to 2024. Although this study does not establish causation, it highlights a strong correlation between changes in migratory timing and sea ice coverage in the whales’ Antarctic feeding grounds. The observed decline in sea ice area, combined with the large increase in the humpback whale population, are discussed as potential factors contributing to the shift in migratory timing. |
| format | Article |
| id | doaj-art-1e68bd6cc91845adb8a32725b0c6934d |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Nature Portfolio |
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| series | Scientific Reports |
| spelling | doaj-art-1e68bd6cc91845adb8a32725b0c6934d2025-08-20T03:45:24ZengNature PortfolioScientific Reports2045-23222025-07-0115111510.1038/s41598-025-07010-9Southern Ocean humpback whales are shifting to an earlier return migrationRebecca Dunlop0Emma Gumley1Ella Holding McGrath2Michael Noad3School of the Environment, University of QueenslandSchool of the Environment, University of QueenslandSchool of the Environment, University of QueenslandSchool of Veterinary Science, University of QueenslandAbstract The Southern Ocean ecosystem is undergoing unprecedented environmental changes, which have led to shifts in the primary food source of baleen whales, Antarctic krill. Additionally, many humpback whale populations have rebounded from near extirpation due to historical whaling, increasing pressure on now vulnerable krill populations. Since humpback whales rely on energy reserves built up during their feeding season to sustain them during migration, changes in their food supply are likely to influence their migration strategies. In this study, the timing of the ‘return to feeding grounds,’ or southern migration, of the eastern Australian humpback whale population was tracked over a 21-year period. Both land-based and acoustic surveys were used to estimate the timing of the migratory peak in southern Queensland, i.e., the week with the highest number of whales sighted or recorded. Land-based surveys recorded all whales, including females with newborn calves, while acoustic surveys recorded singing adult males. Both datasets revealed that the peak of the southern migration has shifted earlier by approximately three weeks from 2003 to 2024. Although this study does not establish causation, it highlights a strong correlation between changes in migratory timing and sea ice coverage in the whales’ Antarctic feeding grounds. The observed decline in sea ice area, combined with the large increase in the humpback whale population, are discussed as potential factors contributing to the shift in migratory timing.https://doi.org/10.1038/s41598-025-07010-9Antarctic ecosystemHumpback whalesMigrationAcoustic surveyVisual survey |
| spellingShingle | Rebecca Dunlop Emma Gumley Ella Holding McGrath Michael Noad Southern Ocean humpback whales are shifting to an earlier return migration Scientific Reports Antarctic ecosystem Humpback whales Migration Acoustic survey Visual survey |
| title | Southern Ocean humpback whales are shifting to an earlier return migration |
| title_full | Southern Ocean humpback whales are shifting to an earlier return migration |
| title_fullStr | Southern Ocean humpback whales are shifting to an earlier return migration |
| title_full_unstemmed | Southern Ocean humpback whales are shifting to an earlier return migration |
| title_short | Southern Ocean humpback whales are shifting to an earlier return migration |
| title_sort | southern ocean humpback whales are shifting to an earlier return migration |
| topic | Antarctic ecosystem Humpback whales Migration Acoustic survey Visual survey |
| url | https://doi.org/10.1038/s41598-025-07010-9 |
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