Decadal shift in foraging strategy of a migratory southern ocean predator
Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder...
Published in: | Global Change Biology |
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Online Access: | http://hdl.handle.net/2263/80239 https://doi.org/10.1111/gcb.15465 |
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ftunivpretoria:oai:repository.up.ac.za:2263/80239 2023-05-15T14:00:33+02:00 Decadal shift in foraging strategy of a migratory southern ocean predator Van den Berg, Gideon Leon Vermeulen, Els Valenzuela, Luciano O. Berube, Martine Ganswindt, Andre Grocke, Darren R. Hall, Grant Hulva, Pavel Neveceralova, Petra Palsboll, Per J. Carroll, Emma L. 2021-06-07T13:07:00Z http://hdl.handle.net/2263/80239 https://doi.org/10.1111/gcb.15465 en eng Wiley http://hdl.handle.net/2263/80239 Van den Berg, G.L., Vermeulen, E., Valenzuela, L.O. et al. 2021, 'Decadal shift in foraging strategy of a migratory southern ocean predator', Global Change Biology, vol. 27, no. 5, pp. 1052-1067. 1354-1013 (print) 1365-2486 (online) doi:10.1111/gcb.15465 © 2020 John Wiley & Sons Ltd. This is the pre-peer reviewed version of the following article : 'Decadal shift in foraging strategy of a migratory southern ocean predator', Global Change Biology, vol. 27, no. 5, pp. 1052-1067, 2021, doi : 10.1111/gcb.15465. The definite version is available at : http://wileyonlinelibrary.com/journal/gcb. Bayesian mixing model Cetacean Climate change Foraging ecology Indicator species Reproductive success SIBER Southern Ocean Southern right whale (Eubalaena australis) Stable isotopes Postprint Article 2021 ftunivpretoria https://doi.org/10.1111/gcb.15465 2022-05-31T13:30:55Z Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder adaptation to climate change depending on the circumstances. Many baleen whales show philopatry to feeding grounds and are also capital breeders that meet migratory and reproductive costs through seasonal energy intake. Southern right whales (Eubalaena australis, SRWs) are capital breeders that have a strong relationship between reproductive output and foraging success. The population dynamics of South Africa's population of SRWs are characterized by two distinct periods: the 1990s, a period of high calving rates; and the late 2010s, a period associated with lowered calving rates. Here we use analyses of stable carbon (δ13C) and nitrogen (δ15N) isotope values from SRW biopsy samples (n = 122) collected during these two distinct periods to investigate foraging ecology of the South African population of SRWs over a time period coincident with the demographic shift. We show that South African SRWs underwent a dramatic northward shift, and diversification, in foraging strategy from 1990s to 2010s. Bayesian mixing model results suggest that during the 1990s, South African SRWs foraged on prey isotopically similar to South Georgia/Islas Georgias del Sur krill. In contrast, in the 2010s, South African SRWs foraged on prey isotopically consistent with the waters of the Subtropical Convergence, Polar Front and Marion Island. We hypothesize that this shift represents a response to changes in preferred habitat or prey, for example, the decrease in abundance and southward range contraction of Antarctic krill. By linking reproductive decline to changing foraging strategies for the first time in SRWs, we show that altering foraging strategies may not be sufficient to adapt to a changing ocean. Royal Society; Royal Society of New ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill baleen whales Marion Island Southern Ocean Southern Right Whale University of Pretoria: UPSpace Antarctic Southern Ocean Global Change Biology 27 5 1052 1067 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Bayesian mixing model Cetacean Climate change Foraging ecology Indicator species Reproductive success SIBER Southern Ocean Southern right whale (Eubalaena australis) Stable isotopes |
spellingShingle |
Bayesian mixing model Cetacean Climate change Foraging ecology Indicator species Reproductive success SIBER Southern Ocean Southern right whale (Eubalaena australis) Stable isotopes Van den Berg, Gideon Leon Vermeulen, Els Valenzuela, Luciano O. Berube, Martine Ganswindt, Andre Grocke, Darren R. Hall, Grant Hulva, Pavel Neveceralova, Petra Palsboll, Per J. Carroll, Emma L. Decadal shift in foraging strategy of a migratory southern ocean predator |
topic_facet |
Bayesian mixing model Cetacean Climate change Foraging ecology Indicator species Reproductive success SIBER Southern Ocean Southern right whale (Eubalaena australis) Stable isotopes |
description |
Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder adaptation to climate change depending on the circumstances. Many baleen whales show philopatry to feeding grounds and are also capital breeders that meet migratory and reproductive costs through seasonal energy intake. Southern right whales (Eubalaena australis, SRWs) are capital breeders that have a strong relationship between reproductive output and foraging success. The population dynamics of South Africa's population of SRWs are characterized by two distinct periods: the 1990s, a period of high calving rates; and the late 2010s, a period associated with lowered calving rates. Here we use analyses of stable carbon (δ13C) and nitrogen (δ15N) isotope values from SRW biopsy samples (n = 122) collected during these two distinct periods to investigate foraging ecology of the South African population of SRWs over a time period coincident with the demographic shift. We show that South African SRWs underwent a dramatic northward shift, and diversification, in foraging strategy from 1990s to 2010s. Bayesian mixing model results suggest that during the 1990s, South African SRWs foraged on prey isotopically similar to South Georgia/Islas Georgias del Sur krill. In contrast, in the 2010s, South African SRWs foraged on prey isotopically consistent with the waters of the Subtropical Convergence, Polar Front and Marion Island. We hypothesize that this shift represents a response to changes in preferred habitat or prey, for example, the decrease in abundance and southward range contraction of Antarctic krill. By linking reproductive decline to changing foraging strategies for the first time in SRWs, we show that altering foraging strategies may not be sufficient to adapt to a changing ocean. Royal Society; Royal Society of New ... |
format |
Article in Journal/Newspaper |
author |
Van den Berg, Gideon Leon Vermeulen, Els Valenzuela, Luciano O. Berube, Martine Ganswindt, Andre Grocke, Darren R. Hall, Grant Hulva, Pavel Neveceralova, Petra Palsboll, Per J. Carroll, Emma L. |
author_facet |
Van den Berg, Gideon Leon Vermeulen, Els Valenzuela, Luciano O. Berube, Martine Ganswindt, Andre Grocke, Darren R. Hall, Grant Hulva, Pavel Neveceralova, Petra Palsboll, Per J. Carroll, Emma L. |
author_sort |
Van den Berg, Gideon Leon |
title |
Decadal shift in foraging strategy of a migratory southern ocean predator |
title_short |
Decadal shift in foraging strategy of a migratory southern ocean predator |
title_full |
Decadal shift in foraging strategy of a migratory southern ocean predator |
title_fullStr |
Decadal shift in foraging strategy of a migratory southern ocean predator |
title_full_unstemmed |
Decadal shift in foraging strategy of a migratory southern ocean predator |
title_sort |
decadal shift in foraging strategy of a migratory southern ocean predator |
publisher |
Wiley |
publishDate |
2021 |
url |
http://hdl.handle.net/2263/80239 https://doi.org/10.1111/gcb.15465 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctic Krill baleen whales Marion Island Southern Ocean Southern Right Whale |
genre_facet |
Antarc* Antarctic Antarctic Krill baleen whales Marion Island Southern Ocean Southern Right Whale |
op_relation |
http://hdl.handle.net/2263/80239 Van den Berg, G.L., Vermeulen, E., Valenzuela, L.O. et al. 2021, 'Decadal shift in foraging strategy of a migratory southern ocean predator', Global Change Biology, vol. 27, no. 5, pp. 1052-1067. 1354-1013 (print) 1365-2486 (online) doi:10.1111/gcb.15465 |
op_rights |
© 2020 John Wiley & Sons Ltd. This is the pre-peer reviewed version of the following article : 'Decadal shift in foraging strategy of a migratory southern ocean predator', Global Change Biology, vol. 27, no. 5, pp. 1052-1067, 2021, doi : 10.1111/gcb.15465. The definite version is available at : http://wileyonlinelibrary.com/journal/gcb. |
op_doi |
https://doi.org/10.1111/gcb.15465 |
container_title |
Global Change Biology |
container_volume |
27 |
container_issue |
5 |
container_start_page |
1052 |
op_container_end_page |
1067 |
_version_ |
1766269722119110656 |