Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean
Species with similar ecological requirements that overlap in range tend to segregate their niches to minimize competition for resources. However, the niche segregation possibilities for centrally foraging predators that breed on isolated Subantarctic islands may be reduced by spatial constraints and...
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Norwegian Polar Institute
2022
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Online Access: | https://polarresearch.net/index.php/polar/article/view/6351 https://doi.org/10.33265/polar.v41.6351 |
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ftjpolarres:oai:journals.openacademia.net:article/6351 2023-05-15T14:01:21+02:00 Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean Narvestad, Audun Kovacs, Kit M. Lydersen, Christian Lowther, Andrew D. 2022-03-11 text/html application/pdf application/epub+zip text/xml https://polarresearch.net/index.php/polar/article/view/6351 https://doi.org/10.33265/polar.v41.6351 eng eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/6351/14441 https://polarresearch.net/index.php/polar/article/view/6351/14446 https://polarresearch.net/index.php/polar/article/view/6351/14442 https://polarresearch.net/index.php/polar/article/view/6351/14445 https://polarresearch.net/index.php/polar/article/view/6351 doi:10.33265/polar.v41.6351 Copyright (c) 2022 Audun Narvestad, Kit M. Kovacs, Christian Lydersen, Andrew D. Lowther https://creativecommons.org/licenses/by-nc/4.0 CC-BY-NC Polar Research; Vol. 41 (2022) 1751-8369 Ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftjpolarres https://doi.org/10.33265/polar.v41.6351 2023-01-04T23:49:34Z Species with similar ecological requirements that overlap in range tend to segregate their niches to minimize competition for resources. However, the niche segregation possibilities for centrally foraging predators that breed on isolated Subantarctic islands may be reduced by spatial constraints and limitations in the availability of alternative prey. In this study we examined spatial and trophic aspects of the foraging niches of two sympatrically breeding penguin species, macaroni (Eudyptes chrysolophus; MAC) and chinstrap (Pygoscelis antarcticus; CHIN) penguins, at Bouvetøya over two breeding seasons. To measure at-sea movements and diving behaviour, 90 MACs and 49 CHINs were equipped with GPS loggers and dive recorders during two austral summer breeding seasons (2014/15 and 2017/18). In addition, blood samples from tracked birds were analysed for stable isotopes to obtain dietary information. CHINs displayed marked interannual variation in foraging behaviour, diving deeper, utilizing a larger foraging area and displaying enriched values of δ15N in 2014/15 compared to the 2017/18 breeding season. In contrast, MACs dove to similar depths and showed similar δ15N values, while consistently utilizing larger foraging areas compared to CHINs. We suggest that low krill abundances in the waters around Bouvetøya during the 2014/15 season resulted in CHINs shifting toward a diet that increased their niche overlap with MACs. Our findings may partly explain the decreasing number of breeding CHINs at the world’s most remote island, Bouvetøya, while also highlighting the importance of characterizing niche overlap of species using multi-season data sets. Article in Journal/Newspaper Antarc* antarcticus Bouvetøya Eudyptes chrysolophus Polar Research Southern Ocean Polar Research (E-Journal) Southern Ocean Austral Bouvetøya ENVELOPE(3.358,3.358,-54.422,-54.422) Polar Research 41 |
institution |
Open Polar |
collection |
Polar Research (E-Journal) |
op_collection_id |
ftjpolarres |
language |
English |
topic |
Ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry |
spellingShingle |
Ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry Narvestad, Audun Kovacs, Kit M. Lydersen, Christian Lowther, Andrew D. Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
topic_facet |
Ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry |
description |
Species with similar ecological requirements that overlap in range tend to segregate their niches to minimize competition for resources. However, the niche segregation possibilities for centrally foraging predators that breed on isolated Subantarctic islands may be reduced by spatial constraints and limitations in the availability of alternative prey. In this study we examined spatial and trophic aspects of the foraging niches of two sympatrically breeding penguin species, macaroni (Eudyptes chrysolophus; MAC) and chinstrap (Pygoscelis antarcticus; CHIN) penguins, at Bouvetøya over two breeding seasons. To measure at-sea movements and diving behaviour, 90 MACs and 49 CHINs were equipped with GPS loggers and dive recorders during two austral summer breeding seasons (2014/15 and 2017/18). In addition, blood samples from tracked birds were analysed for stable isotopes to obtain dietary information. CHINs displayed marked interannual variation in foraging behaviour, diving deeper, utilizing a larger foraging area and displaying enriched values of δ15N in 2014/15 compared to the 2017/18 breeding season. In contrast, MACs dove to similar depths and showed similar δ15N values, while consistently utilizing larger foraging areas compared to CHINs. We suggest that low krill abundances in the waters around Bouvetøya during the 2014/15 season resulted in CHINs shifting toward a diet that increased their niche overlap with MACs. Our findings may partly explain the decreasing number of breeding CHINs at the world’s most remote island, Bouvetøya, while also highlighting the importance of characterizing niche overlap of species using multi-season data sets. |
format |
Article in Journal/Newspaper |
author |
Narvestad, Audun Kovacs, Kit M. Lydersen, Christian Lowther, Andrew D. |
author_facet |
Narvestad, Audun Kovacs, Kit M. Lydersen, Christian Lowther, Andrew D. |
author_sort |
Narvestad, Audun |
title |
Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
title_short |
Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
title_full |
Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
title_fullStr |
Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
title_full_unstemmed |
Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean |
title_sort |
foraging behaviour of sympatrically breeding macaroni (eudyptes chrysolophus) and chinstrap (pygoscelis antarcticus) penguins at bouvetøya, southern ocean |
publisher |
Norwegian Polar Institute |
publishDate |
2022 |
url |
https://polarresearch.net/index.php/polar/article/view/6351 https://doi.org/10.33265/polar.v41.6351 |
long_lat |
ENVELOPE(3.358,3.358,-54.422,-54.422) |
geographic |
Southern Ocean Austral Bouvetøya |
geographic_facet |
Southern Ocean Austral Bouvetøya |
genre |
Antarc* antarcticus Bouvetøya Eudyptes chrysolophus Polar Research Southern Ocean |
genre_facet |
Antarc* antarcticus Bouvetøya Eudyptes chrysolophus Polar Research Southern Ocean |
op_source |
Polar Research; Vol. 41 (2022) 1751-8369 |
op_relation |
https://polarresearch.net/index.php/polar/article/view/6351/14441 https://polarresearch.net/index.php/polar/article/view/6351/14446 https://polarresearch.net/index.php/polar/article/view/6351/14442 https://polarresearch.net/index.php/polar/article/view/6351/14445 https://polarresearch.net/index.php/polar/article/view/6351 doi:10.33265/polar.v41.6351 |
op_rights |
Copyright (c) 2022 Audun Narvestad, Kit M. Kovacs, Christian Lydersen, Andrew D. Lowther https://creativecommons.org/licenses/by-nc/4.0 |
op_rightsnorm |
CC-BY-NC |
op_doi |
https://doi.org/10.33265/polar.v41.6351 |
container_title |
Polar Research |
container_volume |
41 |
_version_ |
1766271100533080064 |