Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica
The theory of reproductive effort is commonly viewed in the perspective of the cost of offspring to the parent. This interpretation predicts that older females make a greater reproductive effort than younger females, for whom the cost of lost future offspring is less. The benefit early‐born offsprin...
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Language: | English |
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Wiley
1986
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Online Access: | http://dx.doi.org/10.1111/j.1469-7998.1986.tb01519.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1986.tb01519.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x |
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crwiley:10.1111/j.1469-7998.1986.tb01519.x 2024-06-02T08:07:48+00:00 Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica Atewart, Robert E. A. 1986 http://dx.doi.org/10.1111/j.1469-7998.1986.tb01519.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1986.tb01519.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Zoology volume 208, issue 4, page 503-517 ISSN 0952-8369 1469-7998 journal-article 1986 crwiley https://doi.org/10.1111/j.1469-7998.1986.tb01519.x 2024-05-03T10:39:52Z The theory of reproductive effort is commonly viewed in the perspective of the cost of offspring to the parent. This interpretation predicts that older females make a greater reproductive effort than younger females, for whom the cost of lost future offspring is less. The benefit early‐born offspring represent in future generations is greater than that of late‐born offspring in most natural populations, so, alternatively, young females should make a greater reproductive effort. These hypotheses were investigated in nursing Harp seals by examining age‐specific reproductive effort in terms of energetic maternal investment. Younger Harp seal females lost weight at the same rate as did older females. Moreover. since younger, growing females tended to start lactation with less blubber than older females. weight loss during 10 days (d) of lactation represented a greater proportion of stored energy for young females. A successfully weaned pup, therefore, constituted a greater reproductive effort for them than for older females, consistent with benefit–oriented predictions from theory. A model is presented to outline the components of an annual energy budget for female Harp seals in the context of reproductive effort. This model indicates that young females may devote a greater proportion of their annual net energy to reproduction and take a greater risk of lost future reproduction. It also identifies areas of inadequacy of existing data on pinniped energy budgets. Article in Journal/Newspaper Harp Seal Phoca groenlandica Wiley Online Library Journal of Zoology 208 4 503 517 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
The theory of reproductive effort is commonly viewed in the perspective of the cost of offspring to the parent. This interpretation predicts that older females make a greater reproductive effort than younger females, for whom the cost of lost future offspring is less. The benefit early‐born offspring represent in future generations is greater than that of late‐born offspring in most natural populations, so, alternatively, young females should make a greater reproductive effort. These hypotheses were investigated in nursing Harp seals by examining age‐specific reproductive effort in terms of energetic maternal investment. Younger Harp seal females lost weight at the same rate as did older females. Moreover. since younger, growing females tended to start lactation with less blubber than older females. weight loss during 10 days (d) of lactation represented a greater proportion of stored energy for young females. A successfully weaned pup, therefore, constituted a greater reproductive effort for them than for older females, consistent with benefit–oriented predictions from theory. A model is presented to outline the components of an annual energy budget for female Harp seals in the context of reproductive effort. This model indicates that young females may devote a greater proportion of their annual net energy to reproduction and take a greater risk of lost future reproduction. It also identifies areas of inadequacy of existing data on pinniped energy budgets. |
format |
Article in Journal/Newspaper |
author |
Atewart, Robert E. A. |
spellingShingle |
Atewart, Robert E. A. Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
author_facet |
Atewart, Robert E. A. |
author_sort |
Atewart, Robert E. A. |
title |
Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
title_short |
Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
title_full |
Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
title_fullStr |
Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
title_full_unstemmed |
Energetics of age‐specific reproductive effort in female Harp seals, Phoca groenlandica |
title_sort |
energetics of age‐specific reproductive effort in female harp seals, phoca groenlandica |
publisher |
Wiley |
publishDate |
1986 |
url |
http://dx.doi.org/10.1111/j.1469-7998.1986.tb01519.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1986.tb01519.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1986.tb01519.x |
genre |
Harp Seal Phoca groenlandica |
genre_facet |
Harp Seal Phoca groenlandica |
op_source |
Journal of Zoology volume 208, issue 4, page 503-517 ISSN 0952-8369 1469-7998 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1469-7998.1986.tb01519.x |
container_title |
Journal of Zoology |
container_volume |
208 |
container_issue |
4 |
container_start_page |
503 |
op_container_end_page |
517 |
_version_ |
1800752936858419200 |