Prowse, TAA and Johnson, CN and Lacy, RC and Bradshaw, CJA and Pollak, JP and Watts, MJ and Brook, BW, No need for disease: Testing extinction hypotheses for the thylacine using multi-species metamodels, Journal of Animal Ecology, 82, (2) pp. 355-364. ISSN 0021-8790 (2013) [Refereed Article]
Copyright 2013 The Authors. Journal of Animal Ecology copyright 2013 British Ecological Society.
- Population viability analysis (PVA) is widely used to assess the extinction risk of threatened species and to evaluate different management strategies. However, conventional PVA neglects important biotic interactions and therefore can fail to identify important threatening processes.
- We designed a new PVA approach that includes species interactions explicitly by networking species models within a single ‘metamodel’. We demonstrate the utility of PVA metamodels by employing them to reinterpret the extinction of the carnivorous, marsupial thylacine Thylacinus cynocephalus in Tasmania. In particular, we test the claim that well-documented impacts of European settlement cannot account for this extinction and that an unknown disease must have been an additional and necessary cause.
- We first constructed a classical, single-species PVA model for thylacines, which was then extended by incorporation within a dynamic predator–herbivore–vegetation metamodel that accounted for the influence of Europeans on the thylacine's prey base. Given obvious parameter uncertainties, we explored both modelling approaches with rigorous sensitivity analyses.
- Single-species PVA models were unable to recreate the thylacine's extinction unless a high human harvest, small starting population size or low maximum population growth rate was assumed, even if disease effects were included from 1906 to 1909. In contrast, we readily recreated the thylacine's demise using disease-free multi-species metamodels that simulated declines in native prey populations (particularly due to competition with introduced sheep).
- Dynamic, multi-species metamodels provide a simple, flexible framework for studying current species declines and historical extinctions caused by complex, interacting factors.
|Item Type:||Refereed Article|
|Keywords:||extinction, extinction process, population viability analysis, species interactions, VORTEX, METAMODEL MANAGERmarsupial, population modelling|
|Research Division:||Biological Sciences|
|Research Field:||Community ecology (excl. invasive species ecology)|
|Objective Division:||Animal Production and Animal Primary Products|
|Objective Group:||Fisheries - wild caught|
|Objective Field:||Fisheries - wild caught not elsewhere classified|
|UTAS Author:||Johnson, CN (Professor Christopher Johnson)|
|Web of Science® Times Cited:||28|
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