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The current decline of tropical marsupials in Australia: is history repeating?

Fisher, Diana O., Johnson, Christopher N., Lawes, Michael J., Fritz, Susanne A., McCallum, Hamish, Blomberg, Simon P., VanDerWal, Jeremy, Abbott, Brett, Frank, Anke, Legge, Sarah, Letnic, Mike, Thomas, Colette R., Fisher, Alaric, Gordan, Iain J. and Kutt, Alex (2014). The current decline of tropical marsupials in Australia: is history repeating?. Global Ecology and Biogeography: a journal of macroecology,23(2):181-190.

Document type: Journal Article
Citation counts: Altmetric Score Altmetric Score is 24
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IRMA ID 82057923xPUB480
Title The current decline of tropical marsupials in Australia: is history repeating?
Author Fisher, Diana O.
Johnson, Christopher N.
Lawes, Michael J.
Fritz, Susanne A.
McCallum, Hamish
Blomberg, Simon P.
VanDerWal, Jeremy
Abbott, Brett
Frank, Anke
Legge, Sarah
Letnic, Mike
Thomas, Colette R.
Fisher, Alaric
Gordan, Iain J.
Kutt, Alex
Journal Name Global Ecology and Biogeography: a journal of macroecology
Publication Date 2014
Volume Number 23
Issue Number 2
ISSN 1466-822X   (check CDU catalogue  open catalogue search in new window)
Scopus ID 2-s2.0-84878652300
Start Page 181
End Page 190
Total Pages 10
Place of Publication United Kingdom
Publisher Wiley-Blackwell Publishing Ltd.
HERDC Category C1 - Journal Article (DIISR)
Abstract Aim
A third of all modern (after 1500) mammal extinctions (24/77) are Australian species. These extinctions have been restricted to southern Australia, predominantly in species of ‘critical weight range’ (35–5500 g) in drier climate zones. Introduced red foxes (Vulpes vulpes) that prey on species in this range are often blamed. A new wave of declines is now affecting a globally significant proportion of marsupial species (19 species) in the fox-free northern tropics. We aim to test plausible causes of recent declines in range and determine if mechanisms differ between current tropical declines and past declines, which were in southern (non-tropical) regions.

Location

Australian continent

Methods

We used multiple regression and random forest models to analyse traits that were associated with declines in species range, and compare variables associated with past extinctions in the southern zones with current tropical (northern) declines.

Results

The same two key variables, body mass and habitat structure, were associated with proportion-of-decline in range throughout the continent, but the form of relationships differs with latitude. In the south, medium-sized species in open habitats of lower rainfall were most likely to decline. In the tropics, small species that occupy open vegetation with moderate rainfall (savanna) are now experiencing the most severe declines. Throughout the continent, large-bodied species and those in structurally complex habitats (rainforest) are secure.

Main conclusions

Our results indicate that there is no mid-sized ‘critical weight range’ in the north. Because foxes are absent from the tropics, we suggest that northern Australian marsupial declines are associated with predation by feral cats (Felis catus) exacerbated by reduced ground level vegetation in non-rainforest habitats. To test this, we recommend experiments to remove cats from some locations where tropical mammals are threatened. Our results show that comparative analysis can help to diagnose potential causes of multi-species decline.
Keywords Comparative methods
critical weight range
introduced predators
mammal extinction
marsupials
random forest models
tropical conservation
DOI http://dx.doi.org/10.1111/geb.12088   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
 
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Created: Thu, 07 Aug 2014, 17:01:47 CST