Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island.
International audience Diving behaviour was investigated in female subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island, Indian Ocean. Data were col- lected using electronic Time Depth Recorders on 19 seals during their ®rst foraging trip after parturition in December, fora...
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ftunivrochelle:oai:HAL:hal-00193446v1 2024-02-11T09:55:12+01:00 Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. Georges, Jean-Yves Tremblay, Yann Guinet, Christophe Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Laboratoire de Biochimie et Biologie Marines La Rochelle Université (ULR) 2000 https://hal.science/hal-00193446 en eng HAL CCSD Springer Verlag hal-00193446 https://hal.science/hal-00193446 ISSN: 0722-4060 EISSN: 1432-2056 Polar Biology https://hal.science/hal-00193446 Polar Biology, 2000, 23, pp.59-69 [SDE.BE]Environmental Sciences/Biodiversity and Ecology info:eu-repo/semantics/article Journal articles 2000 ftunivrochelle 2024-01-23T23:35:21Z International audience Diving behaviour was investigated in female subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island, Indian Ocean. Data were col- lected using electronic Time Depth Recorders on 19 seals during their ®rst foraging trip after parturition in December, foraging trips later in summer, and during winter. Subantarctic fur seals at Amsterdam Island are nocturnal, shallow divers. Ninety-nine percent of re- corded dives occurred at night. The diel dive pattern and changes in dive parameters throughout the night suggest that fur seals follow the nycthemeral migrations of their main prey. Seasonal changes in diving behaviour amounted to the fur seals performing progressively deeper and longer dives from their ®rst foraging trip through winter. Dive depth and dive duration increased from the ®rst trip after parturition (16.6 0.5 m and 62.1 1.6 s respectively, n 1000) to summer (19.0 0.4 m and 65 1 s, respectively, n 2000) through winter (29.0 1.0 m and 91.2 2.2 s, re- spectively, n 800). In summer, subantarctic fur seals increased the proportion of time spent at the bottom during dives of between 10 and 20 m, apparently searching for prey when descending to these depths, which corresponded to the oceanic mixed layer. In winter, fur seals behaved similarly when diving between 20 and 50 m, suggesting that the most pro®table depths for feeding moved down during the study period. Most of the dives did not exceed the physiological limits of individuals. Although dive frequency did not vary (10 dives/h of night), the vertical travel distance and the time spent diving increased throughout the study period, while the post-dive interval decreased, indicating that subantarctic fur seals showed a greater diving effort in winter, compared to earlier seasons. Article in Journal/Newspaper Amsterdam Island Polar Biology HAL - Université de La Rochelle Indian |
institution |
Open Polar |
collection |
HAL - Université de La Rochelle |
op_collection_id |
ftunivrochelle |
language |
English |
topic |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology |
spellingShingle |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology Georges, Jean-Yves Tremblay, Yann Guinet, Christophe Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
topic_facet |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology |
description |
International audience Diving behaviour was investigated in female subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island, Indian Ocean. Data were col- lected using electronic Time Depth Recorders on 19 seals during their ®rst foraging trip after parturition in December, foraging trips later in summer, and during winter. Subantarctic fur seals at Amsterdam Island are nocturnal, shallow divers. Ninety-nine percent of re- corded dives occurred at night. The diel dive pattern and changes in dive parameters throughout the night suggest that fur seals follow the nycthemeral migrations of their main prey. Seasonal changes in diving behaviour amounted to the fur seals performing progressively deeper and longer dives from their ®rst foraging trip through winter. Dive depth and dive duration increased from the ®rst trip after parturition (16.6 0.5 m and 62.1 1.6 s respectively, n 1000) to summer (19.0 0.4 m and 65 1 s, respectively, n 2000) through winter (29.0 1.0 m and 91.2 2.2 s, re- spectively, n 800). In summer, subantarctic fur seals increased the proportion of time spent at the bottom during dives of between 10 and 20 m, apparently searching for prey when descending to these depths, which corresponded to the oceanic mixed layer. In winter, fur seals behaved similarly when diving between 20 and 50 m, suggesting that the most pro®table depths for feeding moved down during the study period. Most of the dives did not exceed the physiological limits of individuals. Although dive frequency did not vary (10 dives/h of night), the vertical travel distance and the time spent diving increased throughout the study period, while the post-dive interval decreased, indicating that subantarctic fur seals showed a greater diving effort in winter, compared to earlier seasons. |
author2 |
Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Laboratoire de Biochimie et Biologie Marines La Rochelle Université (ULR) |
format |
Article in Journal/Newspaper |
author |
Georges, Jean-Yves Tremblay, Yann Guinet, Christophe |
author_facet |
Georges, Jean-Yves Tremblay, Yann Guinet, Christophe |
author_sort |
Georges, Jean-Yves |
title |
Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
title_short |
Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
title_full |
Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
title_fullStr |
Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
title_full_unstemmed |
Seasonal diving behaviour in lactating subantarctic fur seals on Amsterdam Island. |
title_sort |
seasonal diving behaviour in lactating subantarctic fur seals on amsterdam island. |
publisher |
HAL CCSD |
publishDate |
2000 |
url |
https://hal.science/hal-00193446 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Amsterdam Island Polar Biology |
genre_facet |
Amsterdam Island Polar Biology |
op_source |
ISSN: 0722-4060 EISSN: 1432-2056 Polar Biology https://hal.science/hal-00193446 Polar Biology, 2000, 23, pp.59-69 |
op_relation |
hal-00193446 https://hal.science/hal-00193446 |
_version_ |
1790594478318288896 |