Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success

1. Prey aggregations, such as fish schools, attract numerous predators. This typically leads to the formation of multi-specific groups of predators. These aggregations can be seen both as a place of increased competition and as a place of possible facilitation between predators. Consequently, the fu...

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Main Authors: Thiebault, Andréa, Semeria, Magali, Lett, Christophe, Tremblay, Yann
Format: Other/Unknown Material
Language:unknown
Published: Zenodo 2016
Subjects:
Online Access:https://doi.org/10.5061/dryad.jv5f8
id ftzenodo:oai:zenodo.org:4933869
record_format openpolar
spelling ftzenodo:oai:zenodo.org:4933869 2024-09-15T18:18:28+00:00 Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success Thiebault, Andréa Semeria, Magali Lett, Christophe Tremblay, Yann 2016-09-22 https://doi.org/10.5061/dryad.jv5f8 unknown Zenodo https://doi.org/10.1111/1365-2656.12455 https://zenodo.org/communities/dryad https://doi.org/10.5061/dryad.jv5f8 oai:zenodo.org:4933869 info:eu-repo/semantics/openAccess Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode Delphinus capensis gannets Tursiops aduncus Carcharhinus brachyurus group-hunting Megaptera novaeangliae foraging sardine run Morus capensis Arctocephalus pusillus pusillus dolphins Holocene info:eu-repo/semantics/other 2016 ftzenodo https://doi.org/10.5061/dryad.jv5f810.1111/1365-2656.12455 2024-07-27T08:06:41Z 1. Prey aggregations, such as fish schools, attract numerous predators. This typically leads to the formation of multi-specific groups of predators. These aggregations can be seen both as a place of increased competition and as a place of possible facilitation between predators. Consequently, the functional role of such predator-prey aggregation is uncertain, and its effect on individual feeding success is virtually unknown. 2. Using underwater film footages of different predators feeding on fish schools during the sardine run in South Africa, we directly measured the in-situ feeding success of individual Cape gannets Morus capensis in different foraging situations. 3. We determined the types of Cape gannet attacks (direct plunge dive or plunge dive followed by underwater pursuit) and we measured the occurrences and timing of attacks from the different species (mostly Cape gannets and long-beaked common dolphins Delphinus capensis). We also estimated the size of the targeted fish schools. These observations were complemented with a simulation model to evaluate the cumulative effect of successive predator attacks on the prey aggregation structure. 4. The probability to capture a fish in one feeding attempt by Cape gannets averaged 0.28. It was lower when gannets engaged in underwater prey pursuit after the plunge compared to direct plunge (0.13 vs. 0.36). We found no effect of the number of prey on gannets' feeding success. However, the timing and frequency of attacks influenced strongly and positively the feeding success of individuals. The probability to capture a fish was the lowest (0.16) when no attack occurred in the few seconds (1-15 s) prior to a dive, and the highest (~0.4, i.e. more than twice) when one or two attacks occurred during this time window. The simulation model showed that a prey aggregation disorganized just after an attack, and that the maximum of disturbance was obtained a few seconds after the initiation of the successive attacks. 5. Our study suggests that, in multi-species predator ... Other/Unknown Material Megaptera novaeangliae Zenodo
institution Open Polar
collection Zenodo
op_collection_id ftzenodo
language unknown
topic Delphinus capensis
gannets
Tursiops aduncus
Carcharhinus brachyurus
group-hunting
Megaptera novaeangliae
foraging
sardine run
Morus capensis
Arctocephalus pusillus pusillus
dolphins
Holocene
spellingShingle Delphinus capensis
gannets
Tursiops aduncus
Carcharhinus brachyurus
group-hunting
Megaptera novaeangliae
foraging
sardine run
Morus capensis
Arctocephalus pusillus pusillus
dolphins
Holocene
Thiebault, Andréa
Semeria, Magali
Lett, Christophe
Tremblay, Yann
Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
topic_facet Delphinus capensis
gannets
Tursiops aduncus
Carcharhinus brachyurus
group-hunting
Megaptera novaeangliae
foraging
sardine run
Morus capensis
Arctocephalus pusillus pusillus
dolphins
Holocene
description 1. Prey aggregations, such as fish schools, attract numerous predators. This typically leads to the formation of multi-specific groups of predators. These aggregations can be seen both as a place of increased competition and as a place of possible facilitation between predators. Consequently, the functional role of such predator-prey aggregation is uncertain, and its effect on individual feeding success is virtually unknown. 2. Using underwater film footages of different predators feeding on fish schools during the sardine run in South Africa, we directly measured the in-situ feeding success of individual Cape gannets Morus capensis in different foraging situations. 3. We determined the types of Cape gannet attacks (direct plunge dive or plunge dive followed by underwater pursuit) and we measured the occurrences and timing of attacks from the different species (mostly Cape gannets and long-beaked common dolphins Delphinus capensis). We also estimated the size of the targeted fish schools. These observations were complemented with a simulation model to evaluate the cumulative effect of successive predator attacks on the prey aggregation structure. 4. The probability to capture a fish in one feeding attempt by Cape gannets averaged 0.28. It was lower when gannets engaged in underwater prey pursuit after the plunge compared to direct plunge (0.13 vs. 0.36). We found no effect of the number of prey on gannets' feeding success. However, the timing and frequency of attacks influenced strongly and positively the feeding success of individuals. The probability to capture a fish was the lowest (0.16) when no attack occurred in the few seconds (1-15 s) prior to a dive, and the highest (~0.4, i.e. more than twice) when one or two attacks occurred during this time window. The simulation model showed that a prey aggregation disorganized just after an attack, and that the maximum of disturbance was obtained a few seconds after the initiation of the successive attacks. 5. Our study suggests that, in multi-species predator ...
format Other/Unknown Material
author Thiebault, Andréa
Semeria, Magali
Lett, Christophe
Tremblay, Yann
author_facet Thiebault, Andréa
Semeria, Magali
Lett, Christophe
Tremblay, Yann
author_sort Thiebault, Andréa
title Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
title_short Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
title_full Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
title_fullStr Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
title_full_unstemmed Data from: How to capture fish in a school? Effect of successive predator attacks on seabird feeding success
title_sort data from: how to capture fish in a school? effect of successive predator attacks on seabird feeding success
publisher Zenodo
publishDate 2016
url https://doi.org/10.5061/dryad.jv5f8
genre Megaptera novaeangliae
genre_facet Megaptera novaeangliae
op_relation https://doi.org/10.1111/1365-2656.12455
https://zenodo.org/communities/dryad
https://doi.org/10.5061/dryad.jv5f8
oai:zenodo.org:4933869
op_rights info:eu-repo/semantics/openAccess
Creative Commons Zero v1.0 Universal
https://creativecommons.org/publicdomain/zero/1.0/legalcode
op_doi https://doi.org/10.5061/dryad.jv5f810.1111/1365-2656.12455
_version_ 1810456591210643456