Multiple-stage decisions in a marine central-place forager
Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place forager...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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The Royal Society
2016-01-01
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| Series: | Royal Society Open Science |
| Subjects: | |
| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.160043 |
| _version_ | 1818383824340385792 |
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| author | Ari S. Friedlaender David W. Johnston Reny B. Tyson Amanda Kaltenberg Jeremy A. Goldbogen Alison K. Stimpert Corrie Curtice Elliott L. Hazen Patrick N. Halpin Andrew J. Read Douglas P. Nowacek |
| author_facet | Ari S. Friedlaender David W. Johnston Reny B. Tyson Amanda Kaltenberg Jeremy A. Goldbogen Alison K. Stimpert Corrie Curtice Elliott L. Hazen Patrick N. Halpin Andrew J. Read Douglas P. Nowacek |
| author_sort | Ari S. Friedlaender |
| collection | DOAJ |
| description | Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies. |
| first_indexed | 2024-12-14T03:12:30Z |
| format | Article |
| id | doaj.art-d9aa895a05c24a8aa9f19bcbcfda458b |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-14T03:12:30Z |
| publishDate | 2016-01-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-d9aa895a05c24a8aa9f19bcbcfda458b2022-12-21T23:19:14ZengThe Royal SocietyRoyal Society Open Science2054-57032016-01-013510.1098/rsos.160043160043Multiple-stage decisions in a marine central-place foragerAri S. FriedlaenderDavid W. JohnstonReny B. TysonAmanda KaltenbergJeremy A. GoldbogenAlison K. StimpertCorrie CurticeElliott L. HazenPatrick N. HalpinAndrew J. ReadDouglas P. NowacekAir-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.160043divingforaging decisionspredator–prey interactions |
| spellingShingle | Ari S. Friedlaender David W. Johnston Reny B. Tyson Amanda Kaltenberg Jeremy A. Goldbogen Alison K. Stimpert Corrie Curtice Elliott L. Hazen Patrick N. Halpin Andrew J. Read Douglas P. Nowacek Multiple-stage decisions in a marine central-place forager Royal Society Open Science diving foraging decisions predator–prey interactions |
| title | Multiple-stage decisions in a marine central-place forager |
| title_full | Multiple-stage decisions in a marine central-place forager |
| title_fullStr | Multiple-stage decisions in a marine central-place forager |
| title_full_unstemmed | Multiple-stage decisions in a marine central-place forager |
| title_short | Multiple-stage decisions in a marine central-place forager |
| title_sort | multiple stage decisions in a marine central place forager |
| topic | diving foraging decisions predator–prey interactions |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.160043 |
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