Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics
BACKGROUND : To understand and predict the distribution of foragers, it is crucial to identify the factors that affect individual movement decisions at different scales. Individuals are expected to adjust their foraging movements to the hierarchical spatial distribution of resources. At a small loca...
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Online Access: | http://hdl.handle.net/2263/75143 https://doi.org/10.1186/s12898-019-0252-x |
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ftunivpretoria:oai:repository.up.ac.za:2263/75143 2023-05-15T14:05:19+02:00 Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics Wege, Mia De Bruyn, P.J. Nico Hindell, Mark A. Lea, Mary‑Anne Bester, Marthan Nieuwoudt 2019-09-11 http://hdl.handle.net/2263/75143 https://doi.org/10.1186/s12898-019-0252-x en eng BioMed Central http://hdl.handle.net/2263/75143 1472-6785 (online) doi:10.1186/s12898-019-0252-x © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License. CC-BY Arctocephalus Boosted regression tree Foraging behaviour Foraging segregation Machine learning Marion Island Niche Sympatry Subantarctic fur seal (Arctocephalus tropicalis) Antarctic fur seal (Arctocephalus gazella) Article 2019 ftunivpretoria https://doi.org/10.1186/s12898-019-0252-x 2022-05-31T13:37:00Z BACKGROUND : To understand and predict the distribution of foragers, it is crucial to identify the factors that affect individual movement decisions at different scales. Individuals are expected to adjust their foraging movements to the hierarchical spatial distribution of resources. At a small local scale, spatial segregation in foraging habitat happens among individuals of closely situated colonies. If foraging segregation is due to differences in distribution of resources, we would expect segregated foraging areas to have divergent habitat characteristics. RESULTS : We investigated how environmental characteristics of preferred foraging areas differ between two closely situated Subantarctic fur seal (Arctocephalus tropicalis) colonies and a single Antarctic fur seal (A. gazella) colony that forage in different pelagic areas even though they are located well within each other’s foraging range. We further investigated the influence of the seasonal cycle on those environmental factors. This study used tracking data from 121 adult female Subantarctic and Antarctic fur seals, collected during summer and winter (2009–2015), from three different colonies. Boosted Regression Tree species distribution models were used to determine key environmental variables associated with areas of fur seal restricted search behaviour. There were no differences in the relative influence of key environmental variables between colonies and seasons. The variables with the most influence for each colony and season were latitude, longitude and magnitude of sea-currents. The influence of latitude and longitude is a by-product of the species’ distinct foraging areas, despite the close proximity (< 25 km) of the colonies. The predicted potential foraging areas for each colony changed from summer to winter, reflecting the seasonal cycle of the Southern Ocean. The model predicted that the potential foraging areas of females from the three colonies should overlap, and the fact they do not in reality indicates that factors other than ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Arctocephalus gazella Marion Island Southern Ocean University of Pretoria: UPSpace Antarctic Southern Ocean BMC Ecology 19 1 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Arctocephalus Boosted regression tree Foraging behaviour Foraging segregation Machine learning Marion Island Niche Sympatry Subantarctic fur seal (Arctocephalus tropicalis) Antarctic fur seal (Arctocephalus gazella) |
spellingShingle |
Arctocephalus Boosted regression tree Foraging behaviour Foraging segregation Machine learning Marion Island Niche Sympatry Subantarctic fur seal (Arctocephalus tropicalis) Antarctic fur seal (Arctocephalus gazella) Wege, Mia De Bruyn, P.J. Nico Hindell, Mark A. Lea, Mary‑Anne Bester, Marthan Nieuwoudt Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
topic_facet |
Arctocephalus Boosted regression tree Foraging behaviour Foraging segregation Machine learning Marion Island Niche Sympatry Subantarctic fur seal (Arctocephalus tropicalis) Antarctic fur seal (Arctocephalus gazella) |
description |
BACKGROUND : To understand and predict the distribution of foragers, it is crucial to identify the factors that affect individual movement decisions at different scales. Individuals are expected to adjust their foraging movements to the hierarchical spatial distribution of resources. At a small local scale, spatial segregation in foraging habitat happens among individuals of closely situated colonies. If foraging segregation is due to differences in distribution of resources, we would expect segregated foraging areas to have divergent habitat characteristics. RESULTS : We investigated how environmental characteristics of preferred foraging areas differ between two closely situated Subantarctic fur seal (Arctocephalus tropicalis) colonies and a single Antarctic fur seal (A. gazella) colony that forage in different pelagic areas even though they are located well within each other’s foraging range. We further investigated the influence of the seasonal cycle on those environmental factors. This study used tracking data from 121 adult female Subantarctic and Antarctic fur seals, collected during summer and winter (2009–2015), from three different colonies. Boosted Regression Tree species distribution models were used to determine key environmental variables associated with areas of fur seal restricted search behaviour. There were no differences in the relative influence of key environmental variables between colonies and seasons. The variables with the most influence for each colony and season were latitude, longitude and magnitude of sea-currents. The influence of latitude and longitude is a by-product of the species’ distinct foraging areas, despite the close proximity (< 25 km) of the colonies. The predicted potential foraging areas for each colony changed from summer to winter, reflecting the seasonal cycle of the Southern Ocean. The model predicted that the potential foraging areas of females from the three colonies should overlap, and the fact they do not in reality indicates that factors other than ... |
format |
Article in Journal/Newspaper |
author |
Wege, Mia De Bruyn, P.J. Nico Hindell, Mark A. Lea, Mary‑Anne Bester, Marthan Nieuwoudt |
author_facet |
Wege, Mia De Bruyn, P.J. Nico Hindell, Mark A. Lea, Mary‑Anne Bester, Marthan Nieuwoudt |
author_sort |
Wege, Mia |
title |
Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
title_short |
Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
title_full |
Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
title_fullStr |
Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
title_full_unstemmed |
Preferred, small‑scale foraging areas of two Southern Ocean fur seal species are not determined by habitat characteristics |
title_sort |
preferred, small‑scale foraging areas of two southern ocean fur seal species are not determined by habitat characteristics |
publisher |
BioMed Central |
publishDate |
2019 |
url |
http://hdl.handle.net/2263/75143 https://doi.org/10.1186/s12898-019-0252-x |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Arctocephalus gazella Marion Island Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Arctocephalus gazella Marion Island Southern Ocean |
op_relation |
http://hdl.handle.net/2263/75143 1472-6785 (online) doi:10.1186/s12898-019-0252-x |
op_rights |
© The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1186/s12898-019-0252-x |
container_title |
BMC Ecology |
container_volume |
19 |
container_issue |
1 |
_version_ |
1766277123901751296 |