Ecological drivers of change at South Georgia: the krill surplus, or climate variability
Macaroni penguins Eudyptes chrysolophus are thought to be one of the most important mesopredators in the Southern Ocean having a greater impact on prey availability and abundance than any other seabird species. Their population centre has long been held to be South Georgia where populations were tho...
Published in: | Ecography |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2012
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1111/j.1600-0587.2012.07330.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.2012.07330.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.2012.07330.x |
id |
crwiley:10.1111/j.1600-0587.2012.07330.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1111/j.1600-0587.2012.07330.x 2024-10-06T13:43:18+00:00 Ecological drivers of change at South Georgia: the krill surplus, or climate variability Trathan, P. N. Ratcliffe, N. Masden, E. A. 2012 http://dx.doi.org/10.1111/j.1600-0587.2012.07330.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.2012.07330.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.2012.07330.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ecography volume 35, issue 11, page 983-993 ISSN 0906-7590 1600-0587 journal-article 2012 crwiley https://doi.org/10.1111/j.1600-0587.2012.07330.x 2024-09-11T04:12:52Z Macaroni penguins Eudyptes chrysolophus are thought to be one of the most important mesopredators in the Southern Ocean having a greater impact on prey availability and abundance than any other seabird species. Their population centre has long been held to be South Georgia where populations were thought to comprise many million animals. Here we report the results of a recent census of the macaroni population at South Georgia undertaken using aerial survey methods. We report dramatic declines in numbers (∼1.0 million breeding pairs) compared to numbers observed in the late 1970s (∼5.4 million pairs), but show that these reductions have occurred principally at sites where numbers had previously been very large. During the breeding season, the main foraging grounds of birds from these sites overlap with the foraging grounds of Antarctic fur seals Arctocephalus gazella , a major competitor for their principal prey, Antarctic krill Euphausia superba . We suggest that the redistribution of the macaroni penguin population at South Georgia reflects the recent recovery of fur seal populations and thus the ongoing consequences of human intervention at South Georgia, a process which started more than 2 centuries previously. The implied resource competition and the observed population changes may also be exacerbated by recent reductions in Antarctic krill abundance which have been linked with reductions in seasonal sea ice following recent, rapid, regional warming in the Antarctic; however, the recovery of fur seal populations, and the ongoing recovery of krill‐eating whale populations argues that tropho‐dynamic interactions may be sufficient to explain the observed changes. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Eudyptes chrysolophus Euphausia superba Macaroni penguin Sea ice Southern Ocean Wiley Online Library Antarctic Southern Ocean The Antarctic Ecography 35 11 983 993 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Macaroni penguins Eudyptes chrysolophus are thought to be one of the most important mesopredators in the Southern Ocean having a greater impact on prey availability and abundance than any other seabird species. Their population centre has long been held to be South Georgia where populations were thought to comprise many million animals. Here we report the results of a recent census of the macaroni population at South Georgia undertaken using aerial survey methods. We report dramatic declines in numbers (∼1.0 million breeding pairs) compared to numbers observed in the late 1970s (∼5.4 million pairs), but show that these reductions have occurred principally at sites where numbers had previously been very large. During the breeding season, the main foraging grounds of birds from these sites overlap with the foraging grounds of Antarctic fur seals Arctocephalus gazella , a major competitor for their principal prey, Antarctic krill Euphausia superba . We suggest that the redistribution of the macaroni penguin population at South Georgia reflects the recent recovery of fur seal populations and thus the ongoing consequences of human intervention at South Georgia, a process which started more than 2 centuries previously. The implied resource competition and the observed population changes may also be exacerbated by recent reductions in Antarctic krill abundance which have been linked with reductions in seasonal sea ice following recent, rapid, regional warming in the Antarctic; however, the recovery of fur seal populations, and the ongoing recovery of krill‐eating whale populations argues that tropho‐dynamic interactions may be sufficient to explain the observed changes. |
format |
Article in Journal/Newspaper |
author |
Trathan, P. N. Ratcliffe, N. Masden, E. A. |
spellingShingle |
Trathan, P. N. Ratcliffe, N. Masden, E. A. Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
author_facet |
Trathan, P. N. Ratcliffe, N. Masden, E. A. |
author_sort |
Trathan, P. N. |
title |
Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
title_short |
Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
title_full |
Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
title_fullStr |
Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
title_full_unstemmed |
Ecological drivers of change at South Georgia: the krill surplus, or climate variability |
title_sort |
ecological drivers of change at south georgia: the krill surplus, or climate variability |
publisher |
Wiley |
publishDate |
2012 |
url |
http://dx.doi.org/10.1111/j.1600-0587.2012.07330.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.2012.07330.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.2012.07330.x |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Eudyptes chrysolophus Euphausia superba Macaroni penguin Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Eudyptes chrysolophus Euphausia superba Macaroni penguin Sea ice Southern Ocean |
op_source |
Ecography volume 35, issue 11, page 983-993 ISSN 0906-7590 1600-0587 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1600-0587.2012.07330.x |
container_title |
Ecography |
container_volume |
35 |
container_issue |
11 |
container_start_page |
983 |
op_container_end_page |
993 |
_version_ |
1812180025707855872 |