Establishing growth chronologies from marine mammal teeth: a method applicable across species
Multidecadal datasets are important for investigating the effects of a changing climate on top predators, particularly if short-term variations are to be differentiated from long-term trends. Annual increments (growth layer groups: GLGs) formed in the teeth of marine mammals have the potential to pr...
Published in: | Journal of Experimental Marine Biology and Ecology |
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Online Access: | https://doi.org/10.1016/j.jembe.2018.04.006 http://ecite.utas.edu.au/131773 |
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ftunivtasecite:oai:ecite.utas.edu.au:131773 2023-05-15T17:59:28+02:00 Establishing growth chronologies from marine mammal teeth: a method applicable across species Hamilton, V Evans, K 2018 https://doi.org/10.1016/j.jembe.2018.04.006 http://ecite.utas.edu.au/131773 en eng Elsevier Science Bv http://dx.doi.org/10.1016/j.jembe.2018.04.006 Hamilton, V and Evans, K, Establishing growth chronologies from marine mammal teeth: a method applicable across species, Journal of Experimental Marine Biology and Ecology, 505 pp. 24-34. ISSN 0022-0981 (2018) [Refereed Article] http://ecite.utas.edu.au/131773 Biological Sciences Ecology Ecological Physiology Refereed Article PeerReviewed 2018 ftunivtasecite https://doi.org/10.1016/j.jembe.2018.04.006 2019-12-13T22:29:41Z Multidecadal datasets are important for investigating the effects of a changing climate on top predators, particularly if short-term variations are to be differentiated from long-term trends. Annual increments (growth layer groups: GLGs) formed in the teeth of marine mammals have the potential to provide multidecadal proxy records or chronologies of energy budgets associated with growth, allowing for the investigation of potential environmental drivers of interannual variability and longer-term changes in growth. To date, methodology universally applicable across marine mammal species for developing such chronologies has not been established. Methodologies developed are often bespoke being developed specifically for individual species and datasets. This thereby limits the applicability of such methodologies to other species and regions and introduces difficulties in the replication of methods. By modifying dendrochronology (tree-ring dating) techniques, we provide a method for developing chronologies from GLG widths using sperm whales ( Physeter macrocephalus ) and long-finned pilot whales ( Globicephala melas ) as examples. The method firstly utilizes statistical crossdating to identify and correct potential errors in GLG identification ensuring assignment of GLGs to the correct calendar year. Common dendrochronology detrending methods were then tested for applicability and the most appropriate applied to remove age-related trends and variability specific to each individual in the example dataset. Finally, individual chronologies comprised of a standardized growth index were calculated and then averaged into a master chronology for each dataset, maximizing common patterns in growth across individuals and reducing noise in the data due to individual variability. The described approach to chronology development provides a number of advantages over others previously used on marine mammals; first, it has been formed on the basis of well-established and tested techniques and second provides a step-by-step process that is readily repeatable, thereby allowing direct comparisons between similarly developed chronologies from different species or regions. Once developed, chronologies can be used in modeling studies and compared with annually resolved climate indices to explore sensitivities in tooth growth and associated energetic budgets to environmental conditions. Article in Journal/Newspaper Physeter macrocephalus eCite UTAS (University of Tasmania) Journal of Experimental Marine Biology and Ecology 505 24 34 |
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eCite UTAS (University of Tasmania) |
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English |
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Biological Sciences Ecology Ecological Physiology |
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Biological Sciences Ecology Ecological Physiology Hamilton, V Evans, K Establishing growth chronologies from marine mammal teeth: a method applicable across species |
topic_facet |
Biological Sciences Ecology Ecological Physiology |
description |
Multidecadal datasets are important for investigating the effects of a changing climate on top predators, particularly if short-term variations are to be differentiated from long-term trends. Annual increments (growth layer groups: GLGs) formed in the teeth of marine mammals have the potential to provide multidecadal proxy records or chronologies of energy budgets associated with growth, allowing for the investigation of potential environmental drivers of interannual variability and longer-term changes in growth. To date, methodology universally applicable across marine mammal species for developing such chronologies has not been established. Methodologies developed are often bespoke being developed specifically for individual species and datasets. This thereby limits the applicability of such methodologies to other species and regions and introduces difficulties in the replication of methods. By modifying dendrochronology (tree-ring dating) techniques, we provide a method for developing chronologies from GLG widths using sperm whales ( Physeter macrocephalus ) and long-finned pilot whales ( Globicephala melas ) as examples. The method firstly utilizes statistical crossdating to identify and correct potential errors in GLG identification ensuring assignment of GLGs to the correct calendar year. Common dendrochronology detrending methods were then tested for applicability and the most appropriate applied to remove age-related trends and variability specific to each individual in the example dataset. Finally, individual chronologies comprised of a standardized growth index were calculated and then averaged into a master chronology for each dataset, maximizing common patterns in growth across individuals and reducing noise in the data due to individual variability. The described approach to chronology development provides a number of advantages over others previously used on marine mammals; first, it has been formed on the basis of well-established and tested techniques and second provides a step-by-step process that is readily repeatable, thereby allowing direct comparisons between similarly developed chronologies from different species or regions. Once developed, chronologies can be used in modeling studies and compared with annually resolved climate indices to explore sensitivities in tooth growth and associated energetic budgets to environmental conditions. |
format |
Article in Journal/Newspaper |
author |
Hamilton, V Evans, K |
author_facet |
Hamilton, V Evans, K |
author_sort |
Hamilton, V |
title |
Establishing growth chronologies from marine mammal teeth: a method applicable across species |
title_short |
Establishing growth chronologies from marine mammal teeth: a method applicable across species |
title_full |
Establishing growth chronologies from marine mammal teeth: a method applicable across species |
title_fullStr |
Establishing growth chronologies from marine mammal teeth: a method applicable across species |
title_full_unstemmed |
Establishing growth chronologies from marine mammal teeth: a method applicable across species |
title_sort |
establishing growth chronologies from marine mammal teeth: a method applicable across species |
publisher |
Elsevier Science Bv |
publishDate |
2018 |
url |
https://doi.org/10.1016/j.jembe.2018.04.006 http://ecite.utas.edu.au/131773 |
genre |
Physeter macrocephalus |
genre_facet |
Physeter macrocephalus |
op_relation |
http://dx.doi.org/10.1016/j.jembe.2018.04.006 Hamilton, V and Evans, K, Establishing growth chronologies from marine mammal teeth: a method applicable across species, Journal of Experimental Marine Biology and Ecology, 505 pp. 24-34. ISSN 0022-0981 (2018) [Refereed Article] http://ecite.utas.edu.au/131773 |
op_doi |
https://doi.org/10.1016/j.jembe.2018.04.006 |
container_title |
Journal of Experimental Marine Biology and Ecology |
container_volume |
505 |
container_start_page |
24 |
op_container_end_page |
34 |
_version_ |
1766168290565029888 |