Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals
1. Foraging theory predicts that predators adjust their movements according to the spatial distribution of prey. Since prey is often patchily distributed, area-restricted search (ARS) behaviour, characterized by sinuous search paths of predators with increased turning frequency, should be effective...
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Language: | English |
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2017
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Online Access: | https://espace.library.uq.edu.au/view/UQ:fa43a72 |
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:fa43a72 2023-05-15T16:05:25+02:00 Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals Adachi, Taiki Costa, Daniel P. Robinson, Patrick W. Peterson, Sarah H. Yamamichi, Masato Naito, Yasuhiko Takahashi, Akinori Goldbogen, Jeremy 2017-02-01 https://espace.library.uq.edu.au/view/UQ:fa43a72 eng eng Wiley-Blackwell doi:10.1111/1365-2435.12686 issn:0269-8463 issn:1365-2435 orcid:0000-0003-2136-3399 23255001 15K14793 12-1 N00014-10-1-0356 N00014-13-1-0134 12J04316 16J02935 Area-Restricted Search 1St-Passage Time Analysis Wandering Albatrosses Marine Predator Behavior Habitat Efficiency Seabirds Patterns Scales Journal Article 2017 ftunivqespace https://doi.org/10.1111/1365-2435.12686 2020-12-08T08:18:18Z 1. Foraging theory predicts that predators adjust their movements according to the spatial distribution of prey. Since prey is often patchily distributed, area-restricted search (ARS) behaviour, characterized by sinuous search paths of predators with increased turning frequency, should be effective in foraging.2. However, it remains unclear whether ARS behaviour actually enhances foraging success in freeranging animals, especially in marine animals that forage in a three-dimensional (3D) environment.3. Here, we reconstructed 3D dive paths of a highly pelagic marine predator, the northern elephant seal (n = 3), with multisensor data loggers that recorded depth, tri-axis acceleration, tri-axis magnetism and swim speed. We identified spatial scales of volume-restricted search (VRS, termed for 3D ARS) behaviour using spherical first-passage time analysis on 3D dive paths, accompanied with quantifying feeding rates in VRS by using mandible accelerometers that recorded feeding events.4. Seals exhibited VRS behaviour at two spatial scales (radius of spheres): small-VRS (8-10 m) and large-VRS (17-19 m). Most feeding events occurred in VRS zones (78 and 86% for small and large-VRS, respectively), although VRS accounted for a small proportion of bottom phase of dives in distance travelled. This suggests a strong link between VRS behaviour and foraging success.5. There was a hierarchical structure to the VRS; most small-VRS (95%) were nested within large-VRS (i. e. nested VRS). Importantly, nested VRS had significantly higher feeding rates than non-nested VRS, because nested VRS contained small- and large-VRS with higher and lower feeding rates, respectively. These results suggest that seals forage on mesopelagic prey in a hierarchical patch system where high-density patches at small scales are nested within lowdensity patches at larger scales.6. We demonstrated that seals employed scale-dependent, hierarchical 3D movements and that underwater fine-scale sinuous movements (i. e. VRS) were strongly linked to higher foraging success, particularly within nested VRS zones. We suggest that seals enhanced foraging success by employing hierarchical movements that possibly reflect the hierarchical property of prey distribution. Although recent studies advocate that optimal searching behaviour would be scale-independent (e. g. Levy walk), our study suggests that scale-dependent processes are important components of successful foraging behaviour. Article in Journal/Newspaper Elephant Seal Elephant Seals The University of Queensland: UQ eSpace Levy ENVELOPE(-66.567,-66.567,-66.320,-66.320) Functional Ecology 31 2 361 369 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Area-Restricted Search 1St-Passage Time Analysis Wandering Albatrosses Marine Predator Behavior Habitat Efficiency Seabirds Patterns Scales |
spellingShingle |
Area-Restricted Search 1St-Passage Time Analysis Wandering Albatrosses Marine Predator Behavior Habitat Efficiency Seabirds Patterns Scales Adachi, Taiki Costa, Daniel P. Robinson, Patrick W. Peterson, Sarah H. Yamamichi, Masato Naito, Yasuhiko Takahashi, Akinori Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
topic_facet |
Area-Restricted Search 1St-Passage Time Analysis Wandering Albatrosses Marine Predator Behavior Habitat Efficiency Seabirds Patterns Scales |
description |
1. Foraging theory predicts that predators adjust their movements according to the spatial distribution of prey. Since prey is often patchily distributed, area-restricted search (ARS) behaviour, characterized by sinuous search paths of predators with increased turning frequency, should be effective in foraging.2. However, it remains unclear whether ARS behaviour actually enhances foraging success in freeranging animals, especially in marine animals that forage in a three-dimensional (3D) environment.3. Here, we reconstructed 3D dive paths of a highly pelagic marine predator, the northern elephant seal (n = 3), with multisensor data loggers that recorded depth, tri-axis acceleration, tri-axis magnetism and swim speed. We identified spatial scales of volume-restricted search (VRS, termed for 3D ARS) behaviour using spherical first-passage time analysis on 3D dive paths, accompanied with quantifying feeding rates in VRS by using mandible accelerometers that recorded feeding events.4. Seals exhibited VRS behaviour at two spatial scales (radius of spheres): small-VRS (8-10 m) and large-VRS (17-19 m). Most feeding events occurred in VRS zones (78 and 86% for small and large-VRS, respectively), although VRS accounted for a small proportion of bottom phase of dives in distance travelled. This suggests a strong link between VRS behaviour and foraging success.5. There was a hierarchical structure to the VRS; most small-VRS (95%) were nested within large-VRS (i. e. nested VRS). Importantly, nested VRS had significantly higher feeding rates than non-nested VRS, because nested VRS contained small- and large-VRS with higher and lower feeding rates, respectively. These results suggest that seals forage on mesopelagic prey in a hierarchical patch system where high-density patches at small scales are nested within lowdensity patches at larger scales.6. We demonstrated that seals employed scale-dependent, hierarchical 3D movements and that underwater fine-scale sinuous movements (i. e. VRS) were strongly linked to higher foraging success, particularly within nested VRS zones. We suggest that seals enhanced foraging success by employing hierarchical movements that possibly reflect the hierarchical property of prey distribution. Although recent studies advocate that optimal searching behaviour would be scale-independent (e. g. Levy walk), our study suggests that scale-dependent processes are important components of successful foraging behaviour. |
author2 |
Goldbogen, Jeremy |
format |
Article in Journal/Newspaper |
author |
Adachi, Taiki Costa, Daniel P. Robinson, Patrick W. Peterson, Sarah H. Yamamichi, Masato Naito, Yasuhiko Takahashi, Akinori |
author_facet |
Adachi, Taiki Costa, Daniel P. Robinson, Patrick W. Peterson, Sarah H. Yamamichi, Masato Naito, Yasuhiko Takahashi, Akinori |
author_sort |
Adachi, Taiki |
title |
Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
title_short |
Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
title_full |
Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
title_fullStr |
Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
title_full_unstemmed |
Searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
title_sort |
searching for prey in a three-dimensional environment: hierarchical movements enhance foraging success in northern elephant seals |
publisher |
Wiley-Blackwell |
publishDate |
2017 |
url |
https://espace.library.uq.edu.au/view/UQ:fa43a72 |
long_lat |
ENVELOPE(-66.567,-66.567,-66.320,-66.320) |
geographic |
Levy |
geographic_facet |
Levy |
genre |
Elephant Seal Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals |
op_relation |
doi:10.1111/1365-2435.12686 issn:0269-8463 issn:1365-2435 orcid:0000-0003-2136-3399 23255001 15K14793 12-1 N00014-10-1-0356 N00014-13-1-0134 12J04316 16J02935 |
op_doi |
https://doi.org/10.1111/1365-2435.12686 |
container_title |
Functional Ecology |
container_volume |
31 |
container_issue |
2 |
container_start_page |
361 |
op_container_end_page |
369 |
_version_ |
1766401312614776832 |