Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks
Abstract Using food supplementation, we tested whether food limits juvenile survival in a population of Northern Goshawks (Accipiter gentilis) in northeastern Utah. The influence of additional food on female nest attendance also was investigated because those strategies may influence predation morta...
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Language: | English |
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Oxford University Press (OUP)
2001
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Online Access: | http://dx.doi.org/10.1093/auk/118.2.352 http://academic.oup.com/auk/article-pdf/118/2/352/29688125/auk0352.pdf |
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croxfordunivpr:10.1093/auk/118.2.352 2024-09-30T14:21:28+00:00 Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks Dewey, Sarah R. Kennedy, Patricia L. 2001 http://dx.doi.org/10.1093/auk/118.2.352 http://academic.oup.com/auk/article-pdf/118/2/352/29688125/auk0352.pdf en eng Oxford University Press (OUP) The Auk volume 118, issue 2, page 352-365 ISSN 1938-4254 0004-8038 journal-article 2001 croxfordunivpr https://doi.org/10.1093/auk/118.2.352 2024-09-03T04:12:04Z Abstract Using food supplementation, we tested whether food limits juvenile survival in a population of Northern Goshawks (Accipiter gentilis) in northeastern Utah. The influence of additional food on female nest attendance also was investigated because those strategies may influence predation mortality rates of juveniles. We provided supplemental food near 13 nests from close to hatching until close to independence during the 1996 and 1997 breeding seasons. Thirteen additional nests served as controls and received no supplemental food. We compared the following variables at treatment and control nests: (1) adult female mass, (2) nestling mass and size, (3) female nest attendance, and (4) juvenile survival. Following supplemental feeding, adult females from treatment nests were heavier than their control counterparts, and remained closer to the nest during the latter part of the nestling period and throughout the postfledging period. Nestlings from supplemented nests were significantly heavier than those from unsupplemented nests, but results for size measurements were equivocal. Survival rates for treatment nestlings were significantly higher than controls in 1997, but not in 1996. Those results support the hypothesis that food does not limit avian reproductive success on an annual basis. Most deaths in 1997 were the result of starvation or sibling competition. That observation, and the fact that fed nestlings were heavier, is consistent with the idea that treatment nestlings were in improved nutritional condition. Overall patterns of mass and nest-attendance for adult female goshawks supports the hypothesis that female condition and behavior are adjusted in response to food supplies. However, it is less clear what role the females' presence in the nest stand plays in mediating juvenile deaths, because we did not document predation as a primary mortality factor during the two years of this study. The apparent flexibility in female nest attendance behavior suggests that such plasticity may be an adaptation to ... Article in Journal/Newspaper Accipiter gentilis Oxford University Press The Auk 118 2 352 365 |
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Oxford University Press |
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description |
Abstract Using food supplementation, we tested whether food limits juvenile survival in a population of Northern Goshawks (Accipiter gentilis) in northeastern Utah. The influence of additional food on female nest attendance also was investigated because those strategies may influence predation mortality rates of juveniles. We provided supplemental food near 13 nests from close to hatching until close to independence during the 1996 and 1997 breeding seasons. Thirteen additional nests served as controls and received no supplemental food. We compared the following variables at treatment and control nests: (1) adult female mass, (2) nestling mass and size, (3) female nest attendance, and (4) juvenile survival. Following supplemental feeding, adult females from treatment nests were heavier than their control counterparts, and remained closer to the nest during the latter part of the nestling period and throughout the postfledging period. Nestlings from supplemented nests were significantly heavier than those from unsupplemented nests, but results for size measurements were equivocal. Survival rates for treatment nestlings were significantly higher than controls in 1997, but not in 1996. Those results support the hypothesis that food does not limit avian reproductive success on an annual basis. Most deaths in 1997 were the result of starvation or sibling competition. That observation, and the fact that fed nestlings were heavier, is consistent with the idea that treatment nestlings were in improved nutritional condition. Overall patterns of mass and nest-attendance for adult female goshawks supports the hypothesis that female condition and behavior are adjusted in response to food supplies. However, it is less clear what role the females' presence in the nest stand plays in mediating juvenile deaths, because we did not document predation as a primary mortality factor during the two years of this study. The apparent flexibility in female nest attendance behavior suggests that such plasticity may be an adaptation to ... |
format |
Article in Journal/Newspaper |
author |
Dewey, Sarah R. Kennedy, Patricia L. |
spellingShingle |
Dewey, Sarah R. Kennedy, Patricia L. Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
author_facet |
Dewey, Sarah R. Kennedy, Patricia L. |
author_sort |
Dewey, Sarah R. |
title |
Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
title_short |
Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
title_full |
Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
title_fullStr |
Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
title_full_unstemmed |
Effects of Supplemental Food on Parental-Care Strategies and Juvenile Survival of Northern Goshawks |
title_sort |
effects of supplemental food on parental-care strategies and juvenile survival of northern goshawks |
publisher |
Oxford University Press (OUP) |
publishDate |
2001 |
url |
http://dx.doi.org/10.1093/auk/118.2.352 http://academic.oup.com/auk/article-pdf/118/2/352/29688125/auk0352.pdf |
genre |
Accipiter gentilis |
genre_facet |
Accipiter gentilis |
op_source |
The Auk volume 118, issue 2, page 352-365 ISSN 1938-4254 0004-8038 |
op_doi |
https://doi.org/10.1093/auk/118.2.352 |
container_title |
The Auk |
container_volume |
118 |
container_issue |
2 |
container_start_page |
352 |
op_container_end_page |
365 |
_version_ |
1811633396549419008 |