Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance
1. Foraging behaviour of Antarctic fur seals rearing pups at Bird Island, South Georgia, was assessed using at-sea activity patterns measured by electronic time- depth recorders. Information was obtained for a total of 75 individuals and 191 foraging trips to sea over five reproductive seasons from...
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ftdeakinunifig:oai:figshare.com:article/20845963 2024-06-23T07:47:47+00:00 Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance IL Boyd John Arnould T Barton JP Croxall 1994-07-01T00:00:00Z http://hdl.handle.net/10536/DRO/DU:30100674 https://figshare.com/articles/journal_contribution/Foraging_behaviour_of_Antarctic_fur_seals_during_periods_of_contrasting_prey_abundance/20845963 unknown http://hdl.handle.net/10536/DRO/DU:30100674 https://figshare.com/articles/journal_contribution/Foraging_behaviour_of_Antarctic_fur_seals_during_periods_of_contrasting_prey_abundance/20845963 All Rights Reserved foraging fur-seal diving behaviour seals krill fur predators animal ecology Text Journal contribution 1994 ftdeakinunifig 2024-06-06T02:05:01Z 1. Foraging behaviour of Antarctic fur seals rearing pups at Bird Island, South Georgia, was assessed using at-sea activity patterns measured by electronic time- depth recorders. Information was obtained for a total of 75 individuals and 191 foraging trips to sea over five reproductive seasons from 1988/89 to 1992/93; this included one season (1990/91) of low prey abundance. A method was developed to divide the diving record up into logical units or bouts which differed from past methods used for defining bouts of behaviour. 2. Foraging trips were significantly longer in 1990/91 than in the other years. There were significant differences between years in the proportion of time spent foraging when at sea and in the distribution of foraging through the day and night. These differences probably represent behavioural responses to changes in prey distribution and abundance and were reflected in the frequency of occurrence of different types of foraging behaviour. 3. Four types of foraging bout were recognized using a cluster analysis. Type I (short) bouts were of short duration (17 min) and occurred mainly during daytime and at dusk. They probably represented exploratory behaviour. Type II (long) bouts occurred mainly at night and were of long duration (80 min). They increased in frequency in 1990/91 when food was scarce and 61-73% of time spent foraging was in these bouts. Type III (shallow) bouts occurred mainly at night, were of short duration (12 min) and represented feeding close to the surface, possibly in association with other, surface-feeding krill predators. Shallow bouts accounted for 8-14% of time spent foraging. Type IV (deep) bouts were of medium duration (19 min) and represented feeding at greater depth (40-50 m) than other bout types. They were most abundant around dawn. 4. Mean dive duration during bouts exceeded the theoretical aerobic dive limit on > 30% of occasions for short, long and deep bouts. There were positive correlations between mean dive duration and surface interval duration for most ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Bird Island DRO - Deakin Research Online Antarctic Bird Island ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
institution |
Open Polar |
collection |
DRO - Deakin Research Online |
op_collection_id |
ftdeakinunifig |
language |
unknown |
topic |
foraging fur-seal diving behaviour seals krill fur predators animal ecology |
spellingShingle |
foraging fur-seal diving behaviour seals krill fur predators animal ecology IL Boyd John Arnould T Barton JP Croxall Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
topic_facet |
foraging fur-seal diving behaviour seals krill fur predators animal ecology |
description |
1. Foraging behaviour of Antarctic fur seals rearing pups at Bird Island, South Georgia, was assessed using at-sea activity patterns measured by electronic time- depth recorders. Information was obtained for a total of 75 individuals and 191 foraging trips to sea over five reproductive seasons from 1988/89 to 1992/93; this included one season (1990/91) of low prey abundance. A method was developed to divide the diving record up into logical units or bouts which differed from past methods used for defining bouts of behaviour. 2. Foraging trips were significantly longer in 1990/91 than in the other years. There were significant differences between years in the proportion of time spent foraging when at sea and in the distribution of foraging through the day and night. These differences probably represent behavioural responses to changes in prey distribution and abundance and were reflected in the frequency of occurrence of different types of foraging behaviour. 3. Four types of foraging bout were recognized using a cluster analysis. Type I (short) bouts were of short duration (17 min) and occurred mainly during daytime and at dusk. They probably represented exploratory behaviour. Type II (long) bouts occurred mainly at night and were of long duration (80 min). They increased in frequency in 1990/91 when food was scarce and 61-73% of time spent foraging was in these bouts. Type III (shallow) bouts occurred mainly at night, were of short duration (12 min) and represented feeding close to the surface, possibly in association with other, surface-feeding krill predators. Shallow bouts accounted for 8-14% of time spent foraging. Type IV (deep) bouts were of medium duration (19 min) and represented feeding at greater depth (40-50 m) than other bout types. They were most abundant around dawn. 4. Mean dive duration during bouts exceeded the theoretical aerobic dive limit on > 30% of occasions for short, long and deep bouts. There were positive correlations between mean dive duration and surface interval duration for most ... |
format |
Article in Journal/Newspaper |
author |
IL Boyd John Arnould T Barton JP Croxall |
author_facet |
IL Boyd John Arnould T Barton JP Croxall |
author_sort |
IL Boyd |
title |
Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
title_short |
Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
title_full |
Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
title_fullStr |
Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
title_full_unstemmed |
Foraging behaviour of Antarctic fur seals during periods of contrasting prey abundance |
title_sort |
foraging behaviour of antarctic fur seals during periods of contrasting prey abundance |
publishDate |
1994 |
url |
http://hdl.handle.net/10536/DRO/DU:30100674 https://figshare.com/articles/journal_contribution/Foraging_behaviour_of_Antarctic_fur_seals_during_periods_of_contrasting_prey_abundance/20845963 |
long_lat |
ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
geographic |
Antarctic Bird Island |
geographic_facet |
Antarctic Bird Island |
genre |
Antarc* Antarctic Antarctic Fur Seals Bird Island |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Bird Island |
op_relation |
http://hdl.handle.net/10536/DRO/DU:30100674 https://figshare.com/articles/journal_contribution/Foraging_behaviour_of_Antarctic_fur_seals_during_periods_of_contrasting_prey_abundance/20845963 |
op_rights |
All Rights Reserved |
_version_ |
1802637944708661248 |