Southern Elephant Seals Replenish Their Lipid Reserves at Different Rates According to Foraging Habitat
International audience Assessing energy gain and expenditure in free ranging marine predators is difficult. However,such measurements are critical if we are to understand how variation in foraging efficiency,and in turn individual body condition, is impacted by environmentally driven changesin prey...
| Published in: | PLOS ONE |
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| Main Authors: | , , , , |
| Other Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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HAL CCSD
2016
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| Subjects: | |
| Online Access: | https://hal.science/hal-01295623 https://doi.org/10.1371/journal.pone.0166747 |
| Summary: | International audience Assessing energy gain and expenditure in free ranging marine predators is difficult. However,such measurements are critical if we are to understand how variation in foraging efficiency,and in turn individual body condition, is impacted by environmentally driven changesin prey abundance and/or accessibility. To investigate the influence of oceanographic habitattype on foraging efficiency, ten post-breeding female southern elephant seals Miroungaleonina (SES) were equipped and tracked with bio-loggers to give continuous information ofprey catch attempts, body density and body activity. Variations in these indices of foragingefficiency were then compared between three different oceanographic habitats, delineatedby the main frontal structures of the Southern Ocean. Results show that changes in bodydensity are related not only to the number of previous prey catch attempts and to the bodyactivity (at a 6 day lag), but also foraging habitat type. For example, despite a lower dailyprey catch attempt rate, SESs foraging north of the sub-Antarctic front improve their bodydensity at a higher rate than individuals foraging south of the sub-Antarctic and polar fronts,suggesting that they may forage on easier to catch and/or more energetically rich prey inthis area. Our study highlights a need to understand the influence of habitat type on toppredator foraging behaviour and efficiency when attempting a better comprehension ofmarine ecosystems.Introduction |
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