Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments
Ontogenetic changes in resource use often delimit transitions between life stages. Ecological and individual factors can cause variation in the timing and consistency of these transitions, ultimately affecting community and population dynamics through changes in growth and survival. Therefore, it is...
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ftoregonstate:ir.library.oregonstate.edu:9s161784g 2024-04-14T08:16:45+00:00 Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments Ramirez, Matthew D. Avens, Larisa Seminoff, Jeffrey A. Goshe, Lisa R. Heppell, Selina S. Fisheries and Wildlife https://ir.library.oregonstate.edu/concern/articles/9s161784g English [eng] eng unknown Ecological Society of America Appendices A and B are available online:: http://dx.doi.org/10.1890/ES15-00255.1.sm https://ir.library.oregonstate.edu/concern/articles/9s161784g Attribution 3.0 United States Article ftoregonstate https://doi.org/10.1890/ES15-00255.1.sm 2024-03-21T15:42:56Z Ontogenetic changes in resource use often delimit transitions between life stages. Ecological and individual factors can cause variation in the timing and consistency of these transitions, ultimately affecting community and population dynamics through changes in growth and survival. Therefore, it is important to document and understand behavioral and life history polymorphisms, and the processes that drive intraspecific variation in them. To evaluate juvenile loggerhead sea turtle (Caretta caretta) life history variation and to detect shifts in habitat and diet that occur during an oceanic-to-neritic ontogenetic shift, we sequentially analyzed the stable isotope composition of humerus bone growth increments from turtles that stranded dead on Southeastern U.S. beaches between 1997 and 2013 (n = 84). In one-half of the sampled turtles, growth increment-specific nitrogen stable isotope (δ¹⁵N) data showed significant increases in δ¹⁵N values over each turtle's life. These data were used to provide a new line of evidence that juvenile Northwest Atlantic loggerheads exhibit two major ontogenetic shift patterns: discrete shifts (n = 24), which were completed within one year, and facultative shifts (n = 14), which were completed over multiple years (up to five). The mean difference in pre- and post-ontogenetic shift δ¹⁵N values was 4.3‰. Differences in isotopic baselines between neritic and oceanic habitats of the Northwest Atlantic Ocean make it likely these patterns are driven by a coupled change in both habitat and diet, and that facultative shifters utilize both neritic and oceanic resources within transitional growth years. Mean size and age at transition between habitats (54.2 cm straightline carapace length, SCL; 11.98 yr) was within the range of previous estimates and did not differ between discrete and facultative shifters. Our results further expand our understanding of loggerhead sea turtle life history polymorphisms and demonstrate the value of bone tissue analysis to the study of this variation. Sequential ... Article in Journal/Newspaper Northwest Atlantic ScholarsArchive@OSU (Oregon State University) |
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ScholarsArchive@OSU (Oregon State University) |
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English unknown |
description |
Ontogenetic changes in resource use often delimit transitions between life stages. Ecological and individual factors can cause variation in the timing and consistency of these transitions, ultimately affecting community and population dynamics through changes in growth and survival. Therefore, it is important to document and understand behavioral and life history polymorphisms, and the processes that drive intraspecific variation in them. To evaluate juvenile loggerhead sea turtle (Caretta caretta) life history variation and to detect shifts in habitat and diet that occur during an oceanic-to-neritic ontogenetic shift, we sequentially analyzed the stable isotope composition of humerus bone growth increments from turtles that stranded dead on Southeastern U.S. beaches between 1997 and 2013 (n = 84). In one-half of the sampled turtles, growth increment-specific nitrogen stable isotope (δ¹⁵N) data showed significant increases in δ¹⁵N values over each turtle's life. These data were used to provide a new line of evidence that juvenile Northwest Atlantic loggerheads exhibit two major ontogenetic shift patterns: discrete shifts (n = 24), which were completed within one year, and facultative shifts (n = 14), which were completed over multiple years (up to five). The mean difference in pre- and post-ontogenetic shift δ¹⁵N values was 4.3‰. Differences in isotopic baselines between neritic and oceanic habitats of the Northwest Atlantic Ocean make it likely these patterns are driven by a coupled change in both habitat and diet, and that facultative shifters utilize both neritic and oceanic resources within transitional growth years. Mean size and age at transition between habitats (54.2 cm straightline carapace length, SCL; 11.98 yr) was within the range of previous estimates and did not differ between discrete and facultative shifters. Our results further expand our understanding of loggerhead sea turtle life history polymorphisms and demonstrate the value of bone tissue analysis to the study of this variation. Sequential ... |
author2 |
Fisheries and Wildlife |
format |
Article in Journal/Newspaper |
author |
Ramirez, Matthew D. Avens, Larisa Seminoff, Jeffrey A. Goshe, Lisa R. Heppell, Selina S. |
spellingShingle |
Ramirez, Matthew D. Avens, Larisa Seminoff, Jeffrey A. Goshe, Lisa R. Heppell, Selina S. Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
author_facet |
Ramirez, Matthew D. Avens, Larisa Seminoff, Jeffrey A. Goshe, Lisa R. Heppell, Selina S. |
author_sort |
Ramirez, Matthew D. |
title |
Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
title_short |
Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
title_full |
Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
title_fullStr |
Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
title_full_unstemmed |
Patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
title_sort |
patterns of loggerhead turtle ontogenetic shifts revealed through isotopic analysis of annual skeletal growth increments |
publisher |
Ecological Society of America |
url |
https://ir.library.oregonstate.edu/concern/articles/9s161784g |
genre |
Northwest Atlantic |
genre_facet |
Northwest Atlantic |
op_relation |
Appendices A and B are available online:: http://dx.doi.org/10.1890/ES15-00255.1.sm https://ir.library.oregonstate.edu/concern/articles/9s161784g |
op_rights |
Attribution 3.0 United States |
op_doi |
https://doi.org/10.1890/ES15-00255.1.sm |
_version_ |
1796315481391497216 |