A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands
Subantarctic skuas Catharacta antarctica are key predators of burrowing petrels at sub-Antarctic islands, and can be used to monitor the health of burrowing petrel populations. A survey of skuas at the Prince Edward Islands was conducted during December 2008, repeating a previous survey in December...
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ftjafricanj:oai:ojs.ajol.info:article/49227 2023-05-15T13:37:10+02:00 A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands Ryan, PG Whittington, PA Crawford, RJM 2009-12-18 application/pdf http://www.ajol.info/index.php/ajms/article/view/49227 eng eng NISC http://www.ajol.info/index.php/ajms/article/view/49227/35565 http://www.ajol.info/index.php/ajms/article/view/49227 Copyright for articles published in this journal is retained by the publisher. African Journal of Marine Science; Vol 31, No 3 (2009) 1814-232X info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article 2009 ftjafricanj 2017-03-05T06:44:53Z Subantarctic skuas Catharacta antarctica are key predators of burrowing petrels at sub-Antarctic islands, and can be used to monitor the health of burrowing petrel populations. A survey of skuas at the Prince Edward Islands was conducted during December 2008, repeating a previous survey in December 2001. Prince Edward Island (46 km2) remains free of introduced mammals, whereas Marion Island (290 km2) had a feral population of cats from the 1950s to 1980s, and still supports a large population of introduced house mice Mus musculus. Breeding skuas were more widespread, occurred at greater densities and extended to higher elevations at Prince Edward Island than Marion Island. Prince Edward Island also supported twice as many non-breeding birds. Burrowing petrels comprised 96% of prey in skua middens at Prince Edward Island compared to only 22% on Marion Island where penguins are more important. The numbers of breeding pairs at Prince Edward Island increased from 2001 to 2008, probably as a result of better coverage in 2008, whereas the number of skua nests on Marion Island was barely half that counted in 2001, continuing an apparent decrease in this species at Marion Island since the 1980s. There is no evidence that removal of cats from Marion Island in the early 1990s has benefited the major native predator of burrowing petrels. Keywords: burrowing petrels; Catharacta; diet; distribution; Marion Island; population size; Prince Edward IslandAfrican Journal of Marine Science 2009, 31(3): 431–437 Article in Journal/Newspaper Antarc* Antarctic Antarctica Marion Island Prince Edward Islands Prince Edward Island AJOL - African Journals Online Antarctic |
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AJOL - African Journals Online |
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ftjafricanj |
language |
English |
description |
Subantarctic skuas Catharacta antarctica are key predators of burrowing petrels at sub-Antarctic islands, and can be used to monitor the health of burrowing petrel populations. A survey of skuas at the Prince Edward Islands was conducted during December 2008, repeating a previous survey in December 2001. Prince Edward Island (46 km2) remains free of introduced mammals, whereas Marion Island (290 km2) had a feral population of cats from the 1950s to 1980s, and still supports a large population of introduced house mice Mus musculus. Breeding skuas were more widespread, occurred at greater densities and extended to higher elevations at Prince Edward Island than Marion Island. Prince Edward Island also supported twice as many non-breeding birds. Burrowing petrels comprised 96% of prey in skua middens at Prince Edward Island compared to only 22% on Marion Island where penguins are more important. The numbers of breeding pairs at Prince Edward Island increased from 2001 to 2008, probably as a result of better coverage in 2008, whereas the number of skua nests on Marion Island was barely half that counted in 2001, continuing an apparent decrease in this species at Marion Island since the 1980s. There is no evidence that removal of cats from Marion Island in the early 1990s has benefited the major native predator of burrowing petrels. Keywords: burrowing petrels; Catharacta; diet; distribution; Marion Island; population size; Prince Edward IslandAfrican Journal of Marine Science 2009, 31(3): 431–437 |
format |
Article in Journal/Newspaper |
author |
Ryan, PG Whittington, PA Crawford, RJM |
spellingShingle |
Ryan, PG Whittington, PA Crawford, RJM A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
author_facet |
Ryan, PG Whittington, PA Crawford, RJM |
author_sort |
Ryan, PG |
title |
A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
title_short |
A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
title_full |
A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
title_fullStr |
A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
title_full_unstemmed |
A tale of two islands: contrasting fortunes for Subantarctic skuas at the Prince Edward Islands |
title_sort |
tale of two islands: contrasting fortunes for subantarctic skuas at the prince edward islands |
publisher |
NISC |
publishDate |
2009 |
url |
http://www.ajol.info/index.php/ajms/article/view/49227 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica Marion Island Prince Edward Islands Prince Edward Island |
genre_facet |
Antarc* Antarctic Antarctica Marion Island Prince Edward Islands Prince Edward Island |
op_source |
African Journal of Marine Science; Vol 31, No 3 (2009) 1814-232X |
op_relation |
http://www.ajol.info/index.php/ajms/article/view/49227/35565 http://www.ajol.info/index.php/ajms/article/view/49227 |
op_rights |
Copyright for articles published in this journal is retained by the publisher. |
_version_ |
1766088785565581312 |