King Eider Foraging Effort During the Pre-Breeding Period in Alaska
For reproduction, many arctic-nesting migratory birds rely on nutrients obtained on the breeding grounds, so they devote sufficient time to foraging immediately prior to nesting. However, little is known about the increase in foraging effort necessary to meet the energetic requirements of reproducti...
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American Ornithological Society
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ftbioone:10.1525/cond.2011.100077 2023-07-30T04:01:55+02:00 King Eider Foraging Effort During the Pre-Breeding Period in Alaska Steffen Oppel Abby N. Powell Malcolm G. Butler Steffen Oppel Abby N. Powell Malcolm G. Butler world 2011-02-01 text/HTML https://doi.org/10.1525/cond.2011.100077 en eng American Ornithological Society doi:10.1525/cond.2011.100077 All rights reserved. https://doi.org/10.1525/cond.2011.100077 Text 2011 ftbioone https://doi.org/10.1525/cond.2011.100077 2023-07-09T09:23:28Z For reproduction, many arctic-nesting migratory birds rely on nutrients obtained on the breeding grounds, so they devote sufficient time to foraging immediately prior to nesting. However, little is known about the increase in foraging effort necessary to meet the energetic requirements of reproduction. In early June 2006 and 2008, we quantified the proportion of time spent foraging before breeding by a large sea duck, the King Eider (Somateria spectabilis), on its breeding grounds in northern Alaska. During >235 hours of behavioral observations, both male and female King Eiders spent >50% of the day loafing (resting, sleeping, comfort behavior, or being alert). Females foraged on average 30% of the time (mean 7.2 hr day-1,95% CI 6.0-8.4 hr day-1), three times as much as males (9%; 2.3 hr day-1, 95% CI 1.5–2.8 hr day-1). The most common prey in ponds where the eiders foraged were chironomid larvae and worms ranging in length from 1 to 30 mm. If the King Eider's daily energy expenditure on its breeding grounds is similar to values published for related species, it would need to ingest only 0.2–0.6 g dry mass of invertebrates per minute of foraging to meet its energetic requirements. Males did not lose body mass before breeding, and we assume that their foraging effort was sufficient for energy balance. Therefore, female King Eiders appear to triple their foraging effort over maintenance requirements to meet the energetic challenges of egg formation. Text Arctic King Eider Somateria spectabilis Alaska BioOne Online Journals Arctic The Condor 113 1 52 60 |
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English |
description |
For reproduction, many arctic-nesting migratory birds rely on nutrients obtained on the breeding grounds, so they devote sufficient time to foraging immediately prior to nesting. However, little is known about the increase in foraging effort necessary to meet the energetic requirements of reproduction. In early June 2006 and 2008, we quantified the proportion of time spent foraging before breeding by a large sea duck, the King Eider (Somateria spectabilis), on its breeding grounds in northern Alaska. During >235 hours of behavioral observations, both male and female King Eiders spent >50% of the day loafing (resting, sleeping, comfort behavior, or being alert). Females foraged on average 30% of the time (mean 7.2 hr day-1,95% CI 6.0-8.4 hr day-1), three times as much as males (9%; 2.3 hr day-1, 95% CI 1.5–2.8 hr day-1). The most common prey in ponds where the eiders foraged were chironomid larvae and worms ranging in length from 1 to 30 mm. If the King Eider's daily energy expenditure on its breeding grounds is similar to values published for related species, it would need to ingest only 0.2–0.6 g dry mass of invertebrates per minute of foraging to meet its energetic requirements. Males did not lose body mass before breeding, and we assume that their foraging effort was sufficient for energy balance. Therefore, female King Eiders appear to triple their foraging effort over maintenance requirements to meet the energetic challenges of egg formation. |
author2 |
Steffen Oppel Abby N. Powell Malcolm G. Butler |
format |
Text |
author |
Steffen Oppel Abby N. Powell Malcolm G. Butler |
spellingShingle |
Steffen Oppel Abby N. Powell Malcolm G. Butler King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
author_facet |
Steffen Oppel Abby N. Powell Malcolm G. Butler |
author_sort |
Steffen Oppel |
title |
King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
title_short |
King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
title_full |
King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
title_fullStr |
King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
title_full_unstemmed |
King Eider Foraging Effort During the Pre-Breeding Period in Alaska |
title_sort |
king eider foraging effort during the pre-breeding period in alaska |
publisher |
American Ornithological Society |
publishDate |
2011 |
url |
https://doi.org/10.1525/cond.2011.100077 |
op_coverage |
world |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic King Eider Somateria spectabilis Alaska |
genre_facet |
Arctic King Eider Somateria spectabilis Alaska |
op_source |
https://doi.org/10.1525/cond.2011.100077 |
op_relation |
doi:10.1525/cond.2011.100077 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.1525/cond.2011.100077 |
container_title |
The Condor |
container_volume |
113 |
container_issue |
1 |
container_start_page |
52 |
op_container_end_page |
60 |
_version_ |
1772812657160617984 |