Seal mothers expend more on offspring under favourable conditions and less when resources are limited
Summary In mammals, maternal expenditure on offspring is a complex mix of several factors including the species mating system, offspring sex and the condition and age of the mother. While theory suggests that in polygynous species mothers should wean larger male offspring than females when resources...
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Blackwell Publishing Ltd
2017
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Online Access: | https://doi.org/10.1111/1365-2656.12611 http://www.ncbi.nlm.nih.gov/pubmed/27859273 http://ecite.utas.edu.au/113977 |
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ftunivtasecite:oai:ecite.utas.edu.au:113977 2023-05-15T16:05:24+02:00 Seal mothers expend more on offspring under favourable conditions and less when resources are limited McMahon, CR Harcourt, RG Burton, HR Daniel, O Hindell, MA 2017 https://doi.org/10.1111/1365-2656.12611 http://www.ncbi.nlm.nih.gov/pubmed/27859273 http://ecite.utas.edu.au/113977 en eng Blackwell Publishing Ltd http://dx.doi.org/10.1111/1365-2656.12611 McMahon, CR and Harcourt, RG and Burton, HR and Daniel, O and Hindell, MA, Seal mothers expend more on offspring under favourable conditions and less when resources are limited, Journal of Animal Ecology, 86, (2) pp. 359-370. ISSN 0021-8790 (2017) [Refereed Article] http://www.ncbi.nlm.nih.gov/pubmed/27859273 http://ecite.utas.edu.au/113977 Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) Refereed Article PeerReviewed 2017 ftunivtasecite https://doi.org/10.1111/1365-2656.12611 2019-12-13T22:13:58Z Summary In mammals, maternal expenditure on offspring is a complex mix of several factors including the species mating system, offspring sex and the condition and age of the mother. While theory suggests that in polygynous species mothers should wean larger male offspring than females when resources and maternal conditions allow, the evidence for this remains equivocal. Southern elephant seals are highly dimorphic, polygynous capital breeders existing in an environment with highly variable resources and should therefore provide clear evidence to support the theoretical expectations of differential maternal expenditure in male and female pups. We quantified maternal size (mass and length) and pup size at birth and weaning for 342 elephant seal mothers at Macquarie Island. The study was conducted over 11years of contrasting sea-ice and Southern Annular Mode values, both indices of maternal prey resources. Overall, large females weaned male pups that weighed 17kg (155%) more than female pups. Maternal condition varied by as much as 59kg among years, and was positively related to Southern Annular Mode, and negatively to maximum sea-ice extent. Smaller mothers weaned relatively larger male pups under favourable conditions, this effect was less apparent for larger mothers. We developed a simple model linking environmental variation to maternal masses post-partum, followed by maternal masses post-partum to weaning masses and then weaning masses to pup survival and demonstrated that environmental conditions affected predicted survival so that the pups of small mothers had an estimated 7% increase in first year survival in good vs. bad years compared to 1% for female pups of large mothers. Co-occurrence of environmental quality and conservative reproductive tactics suggests that mothers retain substantial plasticity in maternal care, enhancing their lifetime reproductive success by adjusting reproductive expenditure relative to both prevailing environmental conditions and their own capabilities. Article in Journal/Newspaper Elephant Seal Elephant Seals Macquarie Island Sea ice Southern Elephant Seals eCite UTAS (University of Tasmania) Journal of Animal Ecology 86 2 359 370 |
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Open Polar |
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eCite UTAS (University of Tasmania) |
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ftunivtasecite |
language |
English |
topic |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) |
spellingShingle |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) McMahon, CR Harcourt, RG Burton, HR Daniel, O Hindell, MA Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
topic_facet |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) |
description |
Summary In mammals, maternal expenditure on offspring is a complex mix of several factors including the species mating system, offspring sex and the condition and age of the mother. While theory suggests that in polygynous species mothers should wean larger male offspring than females when resources and maternal conditions allow, the evidence for this remains equivocal. Southern elephant seals are highly dimorphic, polygynous capital breeders existing in an environment with highly variable resources and should therefore provide clear evidence to support the theoretical expectations of differential maternal expenditure in male and female pups. We quantified maternal size (mass and length) and pup size at birth and weaning for 342 elephant seal mothers at Macquarie Island. The study was conducted over 11years of contrasting sea-ice and Southern Annular Mode values, both indices of maternal prey resources. Overall, large females weaned male pups that weighed 17kg (155%) more than female pups. Maternal condition varied by as much as 59kg among years, and was positively related to Southern Annular Mode, and negatively to maximum sea-ice extent. Smaller mothers weaned relatively larger male pups under favourable conditions, this effect was less apparent for larger mothers. We developed a simple model linking environmental variation to maternal masses post-partum, followed by maternal masses post-partum to weaning masses and then weaning masses to pup survival and demonstrated that environmental conditions affected predicted survival so that the pups of small mothers had an estimated 7% increase in first year survival in good vs. bad years compared to 1% for female pups of large mothers. Co-occurrence of environmental quality and conservative reproductive tactics suggests that mothers retain substantial plasticity in maternal care, enhancing their lifetime reproductive success by adjusting reproductive expenditure relative to both prevailing environmental conditions and their own capabilities. |
format |
Article in Journal/Newspaper |
author |
McMahon, CR Harcourt, RG Burton, HR Daniel, O Hindell, MA |
author_facet |
McMahon, CR Harcourt, RG Burton, HR Daniel, O Hindell, MA |
author_sort |
McMahon, CR |
title |
Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
title_short |
Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
title_full |
Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
title_fullStr |
Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
title_full_unstemmed |
Seal mothers expend more on offspring under favourable conditions and less when resources are limited |
title_sort |
seal mothers expend more on offspring under favourable conditions and less when resources are limited |
publisher |
Blackwell Publishing Ltd |
publishDate |
2017 |
url |
https://doi.org/10.1111/1365-2656.12611 http://www.ncbi.nlm.nih.gov/pubmed/27859273 http://ecite.utas.edu.au/113977 |
genre |
Elephant Seal Elephant Seals Macquarie Island Sea ice Southern Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals Macquarie Island Sea ice Southern Elephant Seals |
op_relation |
http://dx.doi.org/10.1111/1365-2656.12611 McMahon, CR and Harcourt, RG and Burton, HR and Daniel, O and Hindell, MA, Seal mothers expend more on offspring under favourable conditions and less when resources are limited, Journal of Animal Ecology, 86, (2) pp. 359-370. ISSN 0021-8790 (2017) [Refereed Article] http://www.ncbi.nlm.nih.gov/pubmed/27859273 http://ecite.utas.edu.au/113977 |
op_doi |
https://doi.org/10.1111/1365-2656.12611 |
container_title |
Journal of Animal Ecology |
container_volume |
86 |
container_issue |
2 |
container_start_page |
359 |
op_container_end_page |
370 |
_version_ |
1766401290698489856 |