Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses
1. Theoretical models predict that animals will vary their effort to maximize different currencies such as time and energy when the constraints of reproduction change during breeding, but this has been poorly studied in free-ranging animals. 2. Foraging effort (energy per unit time) was examined by...
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ftcdlib:qt9bb5r4c5 2023-05-15T16:00:57+02:00 Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses Shaffer, Scott A Costa, Daniel P Weimerskirch, Henri 66 - 74 2003-01-01 application/pdf http://www.escholarship.org/uc/item/9bb5r4c5 english eng eScholarship, University of California qt9bb5r4c5 http://www.escholarship.org/uc/item/9bb5r4c5 public Shaffer, Scott A; Costa, Daniel P; & Weimerskirch, Henri. (2003). Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses. Functional Ecology, 17(1), 66 - 74. UC Santa Cruz: Retrieved from: http://www.escholarship.org/uc/item/9bb5r4c5 Crozet doubly labelled water DLW energetics foraging satellite tracking wandering albatross article 2003 ftcdlib 2016-04-02T18:28:04Z 1. Theoretical models predict that animals will vary their effort to maximize different currencies such as time and energy when the constraints of reproduction change during breeding, but this has been poorly studied in free-ranging animals. 2. Foraging effort (energy per unit time) was examined by comparing mass changes, foraging costs and activity-specific behaviours of Wandering Albatrosses ( Diomedea exulans Linnaeus) during the incubation and chick-brooding stages. In 1998, 38 albatrosses (20 during incubation and 18 during brooding) were injected with doubly labelled water and equipped with satellite transmitters and activity data loggers. 3. During incubation, albatrosses travelled 3·7 times farther and were at sea 3·2 times longer, yet foraging costs were significantly lower than trips made during brooding (incubation 4·52 ± 0·50 SD W kg - 1 vs brooding 4·98 ± 0·55 SD W kg - 1 ). 4. The rate of daily mass gain decreased significantly with time at sea during incubation whereas the rate of daily mass gain increased significantly with time at sea during brooding. 5. Foraging effort was higher during brooding, suggesting that birds were minimizing time at sea to maximize the rate of food delivery to chicks. In contrast, foraging effort was lower during incubation, suggesting that birds were maximizing time at sea and minimizing the energy costs of foraging. 6. Foraging costs were also different between sexes. However, this was related to body size differences and not to differences in foraging effort as suggested in previous studies. Article in Journal/Newspaper Diomedea exulans Wandering Albatross University of California: eScholarship |
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Open Polar |
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University of California: eScholarship |
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ftcdlib |
language |
English |
topic |
Crozet doubly labelled water DLW energetics foraging satellite tracking wandering albatross |
spellingShingle |
Crozet doubly labelled water DLW energetics foraging satellite tracking wandering albatross Shaffer, Scott A Costa, Daniel P Weimerskirch, Henri Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
topic_facet |
Crozet doubly labelled water DLW energetics foraging satellite tracking wandering albatross |
description |
1. Theoretical models predict that animals will vary their effort to maximize different currencies such as time and energy when the constraints of reproduction change during breeding, but this has been poorly studied in free-ranging animals. 2. Foraging effort (energy per unit time) was examined by comparing mass changes, foraging costs and activity-specific behaviours of Wandering Albatrosses ( Diomedea exulans Linnaeus) during the incubation and chick-brooding stages. In 1998, 38 albatrosses (20 during incubation and 18 during brooding) were injected with doubly labelled water and equipped with satellite transmitters and activity data loggers. 3. During incubation, albatrosses travelled 3·7 times farther and were at sea 3·2 times longer, yet foraging costs were significantly lower than trips made during brooding (incubation 4·52 ± 0·50 SD W kg - 1 vs brooding 4·98 ± 0·55 SD W kg - 1 ). 4. The rate of daily mass gain decreased significantly with time at sea during incubation whereas the rate of daily mass gain increased significantly with time at sea during brooding. 5. Foraging effort was higher during brooding, suggesting that birds were minimizing time at sea to maximize the rate of food delivery to chicks. In contrast, foraging effort was lower during incubation, suggesting that birds were maximizing time at sea and minimizing the energy costs of foraging. 6. Foraging costs were also different between sexes. However, this was related to body size differences and not to differences in foraging effort as suggested in previous studies. |
format |
Article in Journal/Newspaper |
author |
Shaffer, Scott A Costa, Daniel P Weimerskirch, Henri |
author_facet |
Shaffer, Scott A Costa, Daniel P Weimerskirch, Henri |
author_sort |
Shaffer, Scott A |
title |
Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
title_short |
Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
title_full |
Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
title_fullStr |
Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
title_full_unstemmed |
Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
title_sort |
foraging effort in relation to the constraints of reproduction in free-ranging albatrosses |
publisher |
eScholarship, University of California |
publishDate |
2003 |
url |
http://www.escholarship.org/uc/item/9bb5r4c5 |
op_coverage |
66 - 74 |
genre |
Diomedea exulans Wandering Albatross |
genre_facet |
Diomedea exulans Wandering Albatross |
op_source |
Shaffer, Scott A; Costa, Daniel P; & Weimerskirch, Henri. (2003). Foraging effort in relation to the constraints of reproduction in free-ranging albatrosses. Functional Ecology, 17(1), 66 - 74. UC Santa Cruz: Retrieved from: http://www.escholarship.org/uc/item/9bb5r4c5 |
op_relation |
qt9bb5r4c5 http://www.escholarship.org/uc/item/9bb5r4c5 |
op_rights |
public |
_version_ |
1766396954585071616 |