Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna
The causes of Sahul’s megafauna extinctions remain uncertain, although several interacting factors were likely responsible. To examine the relative support for hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured model...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2021-03-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/63870 |
| _version_ | 1811202576064970752 |
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| author | Corey JA Bradshaw Christopher N Johnson John Llewelyn Vera Weisbecker Giovanni Strona Frédérik Saltré |
| author_facet | Corey JA Bradshaw Christopher N Johnson John Llewelyn Vera Weisbecker Giovanni Strona Frédérik Saltré |
| author_sort | Corey JA Bradshaw |
| collection | DOAJ |
| description | The causes of Sahul’s megafauna extinctions remain uncertain, although several interacting factors were likely responsible. To examine the relative support for hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured models for 13 extinct megafauna species from five functional/taxonomic groups, as well as 8 extant species within these groups for comparison. Perturbing specific demographic rates individually, we tested which species were more demographically susceptible to extinction, and then compared these relative sensitivities to the fossil-derived extinction chronology. Our models show that the macropodiformes were the least demographically susceptible to extinction, followed by carnivores, monotremes, vombatiform herbivores, and large birds. Five of the eight extant species were as or more susceptible than the extinct species. There was no clear relationship between extinction susceptibility and the extinction chronology for any perturbation scenario, while body mass and generation length explained much of the variation in relative risk. Our results reveal that the actual mechanisms leading to the observed extinction chronology were unlikely related to variation in demographic susceptibility per se, but were possibly driven instead by finer-scale variation in climate change and/or human prey choice and relative hunting success. |
| first_indexed | 2024-04-12T02:40:59Z |
| format | Article |
| id | doaj.art-9b24111899c2438ab0f239006ea04542 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-12T02:40:59Z |
| publishDate | 2021-03-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-9b24111899c2438ab0f239006ea045422022-12-22T03:51:18ZengeLife Sciences Publications LtdeLife2050-084X2021-03-011010.7554/eLife.63870Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafaunaCorey JA Bradshaw0https://orcid.org/0000-0002-5328-7741Christopher N Johnson1https://orcid.org/0000-0002-9719-3771John Llewelyn2https://orcid.org/0000-0002-5379-5631Vera Weisbecker3https://orcid.org/0000-0003-2370-4046Giovanni Strona4https://orcid.org/0000-0003-2294-4013Frédérik Saltré5https://orcid.org/0000-0002-5040-3911Global Ecology <i>Partuyarta Ngadluku Wardli Kuu</i>, College of Science and Engineering, Flinders University, Tarndanya (Adelaide), Australia; ARC Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, AustraliaARC Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, Australia; Dynamics of Eco-Evolutionary Pattern, University of Tasmania, Hobart, AustraliaGlobal Ecology <i>Partuyarta Ngadluku Wardli Kuu</i>, College of Science and Engineering, Flinders University, Tarndanya (Adelaide), Australia; ARC Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, AustraliaARC Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, Australia; College of Science and Engineering, Flinders University, Adelaide, AustraliaFaculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, FinlandGlobal Ecology <i>Partuyarta Ngadluku Wardli Kuu</i>, College of Science and Engineering, Flinders University, Tarndanya (Adelaide), Australia; ARC Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, AustraliaThe causes of Sahul’s megafauna extinctions remain uncertain, although several interacting factors were likely responsible. To examine the relative support for hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured models for 13 extinct megafauna species from five functional/taxonomic groups, as well as 8 extant species within these groups for comparison. Perturbing specific demographic rates individually, we tested which species were more demographically susceptible to extinction, and then compared these relative sensitivities to the fossil-derived extinction chronology. Our models show that the macropodiformes were the least demographically susceptible to extinction, followed by carnivores, monotremes, vombatiform herbivores, and large birds. Five of the eight extant species were as or more susceptible than the extinct species. There was no clear relationship between extinction susceptibility and the extinction chronology for any perturbation scenario, while body mass and generation length explained much of the variation in relative risk. Our results reveal that the actual mechanisms leading to the observed extinction chronology were unlikely related to variation in demographic susceptibility per se, but were possibly driven instead by finer-scale variation in climate change and/or human prey choice and relative hunting success.https://elifesciences.org/articles/63870vombatiformesmacropodiformesflightless birdscarnivoresmarsupialextinction |
| spellingShingle | Corey JA Bradshaw Christopher N Johnson John Llewelyn Vera Weisbecker Giovanni Strona Frédérik Saltré Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna eLife vombatiformes macropodiformes flightless birds carnivores marsupial extinction |
| title | Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna |
| title_full | Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna |
| title_fullStr | Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna |
| title_full_unstemmed | Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna |
| title_short | Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna |
| title_sort | relative demographic susceptibility does not explain the extinction chronology of sahul s megafauna |
| topic | vombatiformes macropodiformes flightless birds carnivores marsupial extinction |
| url | https://elifesciences.org/articles/63870 |
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