Hostname: page-component-7c8c6479df-p566r Total loading time: 0 Render date: 2024-03-28T12:00:11.558Z Has data issue: false hasContentIssue false

Status of white-chinned petrels Procellaria aequinoctialis Linnaeus 1758, at Bird Island, South Georgia

Published online by Cambridge University Press:  06 May 2004

Simon D. Berrow
Affiliation:
British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK
John P. Croxall
Affiliation:
British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK
Sharon D. Grant
Affiliation:
British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK

Abstract

The white-chinned petrel (Procellaria aequinoctialis) is an abundant, widespread petrel breeding in tussock grassland at sub-Antarctic islands. Over the last decade it has been killed in large numbers in temperate and sub-tropical longline fisheries. However no data are available on the global population status. We assessed the status of white-chinned petrels at Bird Island, South Georgia by comparing the distribution and density of occupied burrows in 1981 and 1998. In both surveys white-chinned petrel burrows occurred in one-quarter of the 460–477 36-m2 quadrats surveyed. The total number of burrows in each quadrat was consistent between each survey but we estimate an overall decrease of 28% in those occupied (with considerable variation between sites). Concurrent data on breeding frequency and success showed that white-chinned petrels are essentially annual breeders at Bird Island; breeding success was consistent at around 44%. Significant factors determining densities of occupied burrows were crown height and percent tussock cover (accounting for 77% of variance). The former has decreased significantly, the latter increased significantly between 1981 and 1998 but there was no relationship between white-chinned petrel occupancy rate and habitat modification due to the presence of fur seals (Arctocephalus gazella). This suggests that any population decline is due to factors operating away from the breeding colony, such as those attributed to fishing.

Type
Papers—Life Sciences and Oceanography
Copyright
© Antarctic Science Ltd 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)