Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations
The New Zealand sea lion Phocarctos hookeri historically bred on the New Zealand mainland (South and North Islands). Subsistence hunting and later commercial sealing reduced its distribution to 3 breeding areas at the spatial edges of its historical distribution range, in the Auckland Islands (AI) a...
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Online Access: | https://researchonline.jcu.edu.au/24084/3/24084_Auge_et_al_2011_Accepted_Version.pdf https://researchonline.jcu.edu.au/24084/4/24084_Auge_et_al_2011.pdf |
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ftjamescook:oai:researchonline.jcu.edu.au:24084 2024-02-11T10:02:14+01:00 Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations Augé, A.A. Chilvers, B.L. Moore, A.B. Davis, L.S. 2011-06-27 application/pdf https://researchonline.jcu.edu.au/24084/3/24084_Auge_et_al_2011_Accepted_Version.pdf https://researchonline.jcu.edu.au/24084/4/24084_Auge_et_al_2011.pdf unknown Inter-Research http://dx.doi.org/10.3354/meps09176 https://researchonline.jcu.edu.au/24084/ https://researchonline.jcu.edu.au/24084/3/24084_Auge_et_al_2011_Accepted_Version.pdf https://researchonline.jcu.edu.au/24084/4/24084_Auge_et_al_2011.pdf Augé, A.A., Chilvers, B.L., Moore, A.B., and Davis, L.S. (2011) Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations. Marine Ecology Progress Series, 432. pp. 247-256. open Article PeerReviewed 2011 ftjamescook https://doi.org/10.3354/meps09176 2024-01-22T23:29:39Z The New Zealand sea lion Phocarctos hookeri historically bred on the New Zealand mainland (South and North Islands). Subsistence hunting and later commercial sealing reduced its distribution to 3 breeding areas at the spatial edges of its historical distribution range, in the Auckland Islands (AI) and on Campbell Island. Here, we present foraging areas and foraging trips of female New Zealand sea lions from the Otago Peninsula, where a recolonising population has been found in the core of the historical range of the species. We compare the results with data from the AI in order to assess the theory that the spatial margin of a species' distribution represents the lower end of habitat suitability. Female New Zealand sea lions at Otago had significantly smaller foraging ranges than females at the AI (mean 65% Kernel ranges: 47 ± 25 km2 versus 687 ± 109 km2), made shorter foraging trips (mean 11.8 ± 2.3 h versus 66.2 ± 4.2 h), and spent 40% less time at sea overall. Juvenile females at Otago from age 2 onwards could access foraging grounds used by adult females nursing pups; this is unlikely to be the case at the AI due to the large distances and associated depths of foraging grounds. Our study illustrates the theory that spatial marginality is related to habitat marginality. Existing management measures to mitigate the impact of bycatch in fisheries on declining remnant colonies around the AI were modelled based on populations exploiting optimal habitat. They should now integrate this new information. Article in Journal/Newspaper Auckland Islands James Cook University, Australia: ResearchOnline@JCU Campbell Island ENVELOPE(169.500,169.500,-52.500,-52.500) New Zealand Marine Ecology Progress Series 432 247 256 |
institution |
Open Polar |
collection |
James Cook University, Australia: ResearchOnline@JCU |
op_collection_id |
ftjamescook |
language |
unknown |
description |
The New Zealand sea lion Phocarctos hookeri historically bred on the New Zealand mainland (South and North Islands). Subsistence hunting and later commercial sealing reduced its distribution to 3 breeding areas at the spatial edges of its historical distribution range, in the Auckland Islands (AI) and on Campbell Island. Here, we present foraging areas and foraging trips of female New Zealand sea lions from the Otago Peninsula, where a recolonising population has been found in the core of the historical range of the species. We compare the results with data from the AI in order to assess the theory that the spatial margin of a species' distribution represents the lower end of habitat suitability. Female New Zealand sea lions at Otago had significantly smaller foraging ranges than females at the AI (mean 65% Kernel ranges: 47 ± 25 km2 versus 687 ± 109 km2), made shorter foraging trips (mean 11.8 ± 2.3 h versus 66.2 ± 4.2 h), and spent 40% less time at sea overall. Juvenile females at Otago from age 2 onwards could access foraging grounds used by adult females nursing pups; this is unlikely to be the case at the AI due to the large distances and associated depths of foraging grounds. Our study illustrates the theory that spatial marginality is related to habitat marginality. Existing management measures to mitigate the impact of bycatch in fisheries on declining remnant colonies around the AI were modelled based on populations exploiting optimal habitat. They should now integrate this new information. |
format |
Article in Journal/Newspaper |
author |
Augé, A.A. Chilvers, B.L. Moore, A.B. Davis, L.S. |
spellingShingle |
Augé, A.A. Chilvers, B.L. Moore, A.B. Davis, L.S. Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
author_facet |
Augé, A.A. Chilvers, B.L. Moore, A.B. Davis, L.S. |
author_sort |
Augé, A.A. |
title |
Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
title_short |
Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
title_full |
Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
title_fullStr |
Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
title_full_unstemmed |
Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations |
title_sort |
foraging behaviour indicates marginal marine habitat for new zealand sea lions: remnant versus recolonising populations |
publisher |
Inter-Research |
publishDate |
2011 |
url |
https://researchonline.jcu.edu.au/24084/3/24084_Auge_et_al_2011_Accepted_Version.pdf https://researchonline.jcu.edu.au/24084/4/24084_Auge_et_al_2011.pdf |
long_lat |
ENVELOPE(169.500,169.500,-52.500,-52.500) |
geographic |
Campbell Island New Zealand |
geographic_facet |
Campbell Island New Zealand |
genre |
Auckland Islands |
genre_facet |
Auckland Islands |
op_relation |
http://dx.doi.org/10.3354/meps09176 https://researchonline.jcu.edu.au/24084/ https://researchonline.jcu.edu.au/24084/3/24084_Auge_et_al_2011_Accepted_Version.pdf https://researchonline.jcu.edu.au/24084/4/24084_Auge_et_al_2011.pdf Augé, A.A., Chilvers, B.L., Moore, A.B., and Davis, L.S. (2011) Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations. Marine Ecology Progress Series, 432. pp. 247-256. |
op_rights |
open |
op_doi |
https://doi.org/10.3354/meps09176 |
container_title |
Marine Ecology Progress Series |
container_volume |
432 |
container_start_page |
247 |
op_container_end_page |
256 |
_version_ |
1790598170105872384 |