Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica.
The Weddell seals (Leptonychotes weddellii) are a fast-ice obligate phocid that plays a pivotal role as both predator and prey within the wider Antarctic marine ecosystem. Weddell seals face an uncertain future with the threat of habitat loss and pressures of marine resource extraction from the Sout...
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ftunivcanter:oai:ir.canterbury.ac.nz:10092/102764 2023-05-15T13:59:52+02:00 Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. Aspinwall, Arkady Michael Tadeusz 2021 application/pdf https://hdl.handle.net/10092/102764 https://doi.org/10.26021/11898 English en eng University of Canterbury https://hdl.handle.net/10092/102764 http://dx.doi.org/10.26021/11898 All Rights Reserved https://canterbury.libguides.com/rights/theses Theses / Dissertations 2021 ftunivcanter https://doi.org/10.26021/11898 2022-09-08T13:42:17Z The Weddell seals (Leptonychotes weddellii) are a fast-ice obligate phocid that plays a pivotal role as both predator and prey within the wider Antarctic marine ecosystem. Weddell seals face an uncertain future with the threat of habitat loss and pressures of marine resource extraction from the Southern Ocean. Monitoring of Weddell seal population dynamics provides us with an understanding of wider ecosystem health. Remote sensing technologies such as satellite imagery are increasingly being used to monitor remote populations in the Antarctic. However, satellite imagery needs to be validated by ground-truthing data, and an understanding of Weddell seal behaviour is critical for accurately interpreting Weddell seal counts from space. While the presence of a diurnal haul-out cycle in Weddell seals has been well documented, it is often not corrected for the variation of environmental conditions over a 24-hour period. I review 5,054 images from Cuddeback trail cameras between the 30th of October and 28th December 2017 from Cape Royds, Antarctica for a colony of non-reproductive Weddell seals. I use Generalised Additive Models to correct haul-out behaviour for the environmental variables of temperature, pressure, and wind-speed to determine a more accurate diurnal haul-out pattern. I find that more Weddell seals haul-out when air temperatures are higher, or wind speeds lower. Secondly, the haul-out cycle persists, with most seals hauled-out in the afternoon, and the fewest seals hauled out in the morning. Haul-out patterns can be used to calibrate satellite census counts of Weddell seals, integrating environmental parameters to correct time-of-day patterns may be the next step in generating better population estimates for the Ross Sea region and the wider Antarctic continent. Other/Unknown Material Antarc* Antarctic Antarctica Ross Sea Southern Ocean Weddell Seal Weddell Seals University of Canterbury, Christchurch: UC Research Repository Antarctic Cape Royds ENVELOPE(166.150,166.150,-77.550,-77.550) Ross Sea Royds ENVELOPE(166.150,166.150,-77.550,-77.550) Southern Ocean The Antarctic Weddell |
institution |
Open Polar |
collection |
University of Canterbury, Christchurch: UC Research Repository |
op_collection_id |
ftunivcanter |
language |
English |
description |
The Weddell seals (Leptonychotes weddellii) are a fast-ice obligate phocid that plays a pivotal role as both predator and prey within the wider Antarctic marine ecosystem. Weddell seals face an uncertain future with the threat of habitat loss and pressures of marine resource extraction from the Southern Ocean. Monitoring of Weddell seal population dynamics provides us with an understanding of wider ecosystem health. Remote sensing technologies such as satellite imagery are increasingly being used to monitor remote populations in the Antarctic. However, satellite imagery needs to be validated by ground-truthing data, and an understanding of Weddell seal behaviour is critical for accurately interpreting Weddell seal counts from space. While the presence of a diurnal haul-out cycle in Weddell seals has been well documented, it is often not corrected for the variation of environmental conditions over a 24-hour period. I review 5,054 images from Cuddeback trail cameras between the 30th of October and 28th December 2017 from Cape Royds, Antarctica for a colony of non-reproductive Weddell seals. I use Generalised Additive Models to correct haul-out behaviour for the environmental variables of temperature, pressure, and wind-speed to determine a more accurate diurnal haul-out pattern. I find that more Weddell seals haul-out when air temperatures are higher, or wind speeds lower. Secondly, the haul-out cycle persists, with most seals hauled-out in the afternoon, and the fewest seals hauled out in the morning. Haul-out patterns can be used to calibrate satellite census counts of Weddell seals, integrating environmental parameters to correct time-of-day patterns may be the next step in generating better population estimates for the Ross Sea region and the wider Antarctic continent. |
format |
Other/Unknown Material |
author |
Aspinwall, Arkady Michael Tadeusz |
spellingShingle |
Aspinwall, Arkady Michael Tadeusz Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
author_facet |
Aspinwall, Arkady Michael Tadeusz |
author_sort |
Aspinwall, Arkady Michael Tadeusz |
title |
Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
title_short |
Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
title_full |
Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
title_fullStr |
Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
title_full_unstemmed |
Factors influencing haul-out behaviour in non-reproductive Weddell seals (Leptonychotes weddellii) at Cape Royds, Antarctica. |
title_sort |
factors influencing haul-out behaviour in non-reproductive weddell seals (leptonychotes weddellii) at cape royds, antarctica. |
publisher |
University of Canterbury |
publishDate |
2021 |
url |
https://hdl.handle.net/10092/102764 https://doi.org/10.26021/11898 |
long_lat |
ENVELOPE(166.150,166.150,-77.550,-77.550) ENVELOPE(166.150,166.150,-77.550,-77.550) |
geographic |
Antarctic Cape Royds Ross Sea Royds Southern Ocean The Antarctic Weddell |
geographic_facet |
Antarctic Cape Royds Ross Sea Royds Southern Ocean The Antarctic Weddell |
genre |
Antarc* Antarctic Antarctica Ross Sea Southern Ocean Weddell Seal Weddell Seals |
genre_facet |
Antarc* Antarctic Antarctica Ross Sea Southern Ocean Weddell Seal Weddell Seals |
op_relation |
https://hdl.handle.net/10092/102764 http://dx.doi.org/10.26021/11898 |
op_rights |
All Rights Reserved https://canterbury.libguides.com/rights/theses |
op_doi |
https://doi.org/10.26021/11898 |
_version_ |
1766268780895272960 |