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://doi.org/10.33265/polar.v41.6351 https://doaj.org/article/5b8f01207adb4a649aa23548e8deed3d |
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ftdoajarticles:oai:doaj.org/article:5b8f01207adb4a649aa23548e8deed3d 2023-05-15T13:34:50+02:00 Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean Audun Narvestad Christian Lydersen Kit M. Kovacs Andrew D. Lowther 2022-03-01T00:00:00Z https://doi.org/10.33265/polar.v41.6351 https://doaj.org/article/5b8f01207adb4a649aa23548e8deed3d EN eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/6351/14446 https://doaj.org/toc/0800-0395 https://doaj.org/toc/1751-8369 0800-0395 1751-8369 doi:10.33265/polar.v41.6351 https://doaj.org/article/5b8f01207adb4a649aa23548e8deed3d Polar Research, Vol 41, Pp 1-13 (2022) ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry Environmental sciences GE1-350 Oceanography GC1-1581 article 2022 ftdoajarticles https://doi.org/10.33265/polar.v41.6351 2022-12-31T04:29:48Z 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 Directory of Open Access Journals: DOAJ Articles Austral Bouvetøya ENVELOPE(3.358,3.358,-54.422,-54.422) Southern Ocean Polar Research 41 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry Environmental sciences GE1-350 Oceanography GC1-1581 |
spellingShingle |
ecological niche niche overlap central place foraging competition stable isotope analysis biotelemetry Environmental sciences GE1-350 Oceanography GC1-1581 Audun Narvestad Christian Lydersen Kit M. Kovacs Andrew D. Lowther 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 Environmental sciences GE1-350 Oceanography GC1-1581 |
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 |
Audun Narvestad Christian Lydersen Kit M. Kovacs Andrew D. Lowther |
author_facet |
Audun Narvestad Christian Lydersen Kit M. Kovacs Andrew D. Lowther |
author_sort |
Audun Narvestad |
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://doi.org/10.33265/polar.v41.6351 https://doaj.org/article/5b8f01207adb4a649aa23548e8deed3d |
long_lat |
ENVELOPE(3.358,3.358,-54.422,-54.422) |
geographic |
Austral Bouvetøya Southern Ocean |
geographic_facet |
Austral Bouvetøya Southern Ocean |
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, Pp 1-13 (2022) |
op_relation |
https://polarresearch.net/index.php/polar/article/view/6351/14446 https://doaj.org/toc/0800-0395 https://doaj.org/toc/1751-8369 0800-0395 1751-8369 doi:10.33265/polar.v41.6351 https://doaj.org/article/5b8f01207adb4a649aa23548e8deed3d |
op_doi |
https://doi.org/10.33265/polar.v41.6351 |
container_title |
Polar Research |
container_volume |
41 |
_version_ |
1766058352158179328 |