A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii.
Generally, sigmoid curves are used to describe the growth of animals over their lifetime. However, because growth rates often differ over an animal's lifetime a single curve may not accurately capture the growth. Broken-stick models constrained to pass through a common point have been proposed...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2011-01-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3192044?pdf=render |
| _version_ | 1811218909105225728 |
|---|---|
| author | Clive R McMahon Marie-Jeanne Buscot Natasha L Wiggins Neil Collier John H Maindonald Hamish I McCallum David M J S Bowman |
| author_facet | Clive R McMahon Marie-Jeanne Buscot Natasha L Wiggins Neil Collier John H Maindonald Hamish I McCallum David M J S Bowman |
| author_sort | Clive R McMahon |
| collection | DOAJ |
| description | Generally, sigmoid curves are used to describe the growth of animals over their lifetime. However, because growth rates often differ over an animal's lifetime a single curve may not accurately capture the growth. Broken-stick models constrained to pass through a common point have been proposed to describe the different growth phases, but these are often unsatisfactory because essentially there are still two functions that describe the lifetime growth. To provide a single, converged model to age animals with disparate growth phases we developed a smoothly joining two-phase nonlinear function (SJ2P), tailored to provide a more accurate description of lifetime growth of the macropod, the Tasmanian pademelon Thylogale billardierii. The model consists of the Verhulst logistic function, which describes pouch-phase growth--joining smoothly to the Brody function, which describes post-pouch growth. Results from the model demonstrate that male pademelons grew faster and bigger than females. Our approach provides a practical means of ageing wild pademelons for life history studies but given the high variability of the data used to parametrise the second growth phase of the model, the accuracy of ageing of post-weaned animals is low: accuracy might be improved with collection of longitudinal growth data. This study provides a unique, first robust method that can be used to characterise growth over the lifespan of pademelons. The development of this method is relevant to collecting age-specific vital rates from commonly used wildlife management practices to provide crucial insights into the demographic behaviour of animal populations. |
| first_indexed | 2024-04-12T07:17:14Z |
| format | Article |
| id | doaj.art-77fd655865434577a309f8797046a1ed |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-12T07:17:14Z |
| publishDate | 2011-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-77fd655865434577a309f8797046a1ed2022-12-22T03:42:25ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-01610e2493410.1371/journal.pone.0024934A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii.Clive R McMahonMarie-Jeanne BuscotNatasha L WigginsNeil CollierJohn H MaindonaldHamish I McCallumDavid M J S BowmanGenerally, sigmoid curves are used to describe the growth of animals over their lifetime. However, because growth rates often differ over an animal's lifetime a single curve may not accurately capture the growth. Broken-stick models constrained to pass through a common point have been proposed to describe the different growth phases, but these are often unsatisfactory because essentially there are still two functions that describe the lifetime growth. To provide a single, converged model to age animals with disparate growth phases we developed a smoothly joining two-phase nonlinear function (SJ2P), tailored to provide a more accurate description of lifetime growth of the macropod, the Tasmanian pademelon Thylogale billardierii. The model consists of the Verhulst logistic function, which describes pouch-phase growth--joining smoothly to the Brody function, which describes post-pouch growth. Results from the model demonstrate that male pademelons grew faster and bigger than females. Our approach provides a practical means of ageing wild pademelons for life history studies but given the high variability of the data used to parametrise the second growth phase of the model, the accuracy of ageing of post-weaned animals is low: accuracy might be improved with collection of longitudinal growth data. This study provides a unique, first robust method that can be used to characterise growth over the lifespan of pademelons. The development of this method is relevant to collecting age-specific vital rates from commonly used wildlife management practices to provide crucial insights into the demographic behaviour of animal populations.http://europepmc.org/articles/PMC3192044?pdf=render |
| spellingShingle | Clive R McMahon Marie-Jeanne Buscot Natasha L Wiggins Neil Collier John H Maindonald Hamish I McCallum David M J S Bowman A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. PLoS ONE |
| title | A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. |
| title_full | A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. |
| title_fullStr | A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. |
| title_full_unstemmed | A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. |
| title_short | A two-phase model for smoothly joining disparate growth phases in the macropodid Thylogale billardierii. |
| title_sort | two phase model for smoothly joining disparate growth phases in the macropodid thylogale billardierii |
| url | http://europepmc.org/articles/PMC3192044?pdf=render |
| work_keys_str_mv | AT clivermcmahon atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT mariejeannebuscot atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT natashalwiggins atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT neilcollier atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT johnhmaindonald atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT hamishimccallum atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT davidmjsbowman atwophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT clivermcmahon twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT mariejeannebuscot twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT natashalwiggins twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT neilcollier twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT johnhmaindonald twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT hamishimccallum twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii AT davidmjsbowman twophasemodelforsmoothlyjoiningdisparategrowthphasesinthemacropodidthylogalebillardierii |