Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method
Physically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific st...
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Online Access: | http://hdl.handle.net/2263/39741 https://doi.org/10.1017/S0954102013000059 |
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ftunivpretoria:oai:repository.up.ac.za:2263/39741 2023-05-15T14:14:51+02:00 Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method Postma, Martin Bester, Marthan Nieuwoudt De Bruyn, P.J. Nico 2014-05-08T08:29:42Z http://hdl.handle.net/2263/39741 https://doi.org/10.1017/S0954102013000059 en eng Cambridge University Press http://hdl.handle.net/2263/39741 Postma, M, Bester, MN & De Bruyn PJN 2013, 'Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method', Antarctic Science, vol. 25, no. 6, pp. 731-740. 0954-1020 (print) 1365-2079 (online) doi:10.1017/S0954102013000059 © Antarctic Science Ltd 2013 Breeding season Life history theory Methodology advancement Mirounga leonina Moult Pelagic foraging Article 2014 ftunivpretoria https://doi.org/10.1017/S0954102013000059 2022-05-31T10:49:14Z Physically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific stages in the life cycle of a top marine predator. Female southern elephant seals (n523) at Marion Island were sampled sequentially using photogrammetry and three-dimensional models (based on each photogrammetry project) were built for estimation of body mass. Simple equations were applied to obtain mass at critical instances in their life cycle. Marion Island elephant seal mass data was compared to data obtained from physically weighed elephant seals from King George, South Georgia and Macquarie islands. Females from Marion Island are smaller, but their percentage lactation mass loss is similar to females from these other populations. The similarity of percentage mass loss during lactation between different female populations illustrates the accuracy and practicality of the photogrammetric method over a temporal scale. Photogrammetric mass estimation can be used alongside datasets of physically weighed animals and can greatly benefit ecology and life history studies. http://journals.cambridge.org am2014 Article in Journal/Newspaper Antarctic Science Elephant Seal Elephant Seals Marion Island Mirounga leonina Southern Elephant Seal Southern Elephant Seals University of Pretoria: UPSpace Antarctic Science 25 6 731 740 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Breeding season Life history theory Methodology advancement Mirounga leonina Moult Pelagic foraging |
spellingShingle |
Breeding season Life history theory Methodology advancement Mirounga leonina Moult Pelagic foraging Postma, Martin Bester, Marthan Nieuwoudt De Bruyn, P.J. Nico Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
topic_facet |
Breeding season Life history theory Methodology advancement Mirounga leonina Moult Pelagic foraging |
description |
Physically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific stages in the life cycle of a top marine predator. Female southern elephant seals (n523) at Marion Island were sampled sequentially using photogrammetry and three-dimensional models (based on each photogrammetry project) were built for estimation of body mass. Simple equations were applied to obtain mass at critical instances in their life cycle. Marion Island elephant seal mass data was compared to data obtained from physically weighed elephant seals from King George, South Georgia and Macquarie islands. Females from Marion Island are smaller, but their percentage lactation mass loss is similar to females from these other populations. The similarity of percentage mass loss during lactation between different female populations illustrates the accuracy and practicality of the photogrammetric method over a temporal scale. Photogrammetric mass estimation can be used alongside datasets of physically weighed animals and can greatly benefit ecology and life history studies. http://journals.cambridge.org am2014 |
format |
Article in Journal/Newspaper |
author |
Postma, Martin Bester, Marthan Nieuwoudt De Bruyn, P.J. Nico |
author_facet |
Postma, Martin Bester, Marthan Nieuwoudt De Bruyn, P.J. Nico |
author_sort |
Postma, Martin |
title |
Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
title_short |
Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
title_full |
Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
title_fullStr |
Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
title_full_unstemmed |
Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
title_sort |
spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method |
publisher |
Cambridge University Press |
publishDate |
2014 |
url |
http://hdl.handle.net/2263/39741 https://doi.org/10.1017/S0954102013000059 |
genre |
Antarctic Science Elephant Seal Elephant Seals Marion Island Mirounga leonina Southern Elephant Seal Southern Elephant Seals |
genre_facet |
Antarctic Science Elephant Seal Elephant Seals Marion Island Mirounga leonina Southern Elephant Seal Southern Elephant Seals |
op_relation |
http://hdl.handle.net/2263/39741 Postma, M, Bester, MN & De Bruyn PJN 2013, 'Spatial variation in female southern elephant seal mass change assessed by an accurate non-invasive photogrammetry method', Antarctic Science, vol. 25, no. 6, pp. 731-740. 0954-1020 (print) 1365-2079 (online) doi:10.1017/S0954102013000059 |
op_rights |
© Antarctic Science Ltd 2013 |
op_doi |
https://doi.org/10.1017/S0954102013000059 |
container_title |
Antarctic Science |
container_volume |
25 |
container_issue |
6 |
container_start_page |
731 |
op_container_end_page |
740 |
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1766287230996840448 |