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Influence of rainfall on native mammal populations in southeastern Australia

Wilson, B.A., Lock, M. and Magnusdottir, R. (2007) Influence of rainfall on native mammal populations in southeastern Australia. In: 11th International Mediterranean Ecosystems (MEDECOS) Conference (2007), 2 - 5 September, Perth, Western Australia.


Climate change involving lower rainfall and extended drought periods poses significant threats to vulnerable mammal species, particularly in fragmented ecosystems. Opportunistic Australian desert rodents have been found to increase in numbers following significant rainfall events and undergo declines and population crashes during dry and drought years. These fluctuations in abundance are related to increased food supply and resource depletion respectively (Letnic 2003). In general, population abundance was positively correlated with an index of rainfall with a time lag of between 3-10 months. Timing and intensity of rainfall events in the wet-dry tropics of northern Australia have also been shown to influence the length of the breeding season, and therefore, population abundance in some Rattus species. There is also recent evidence that low rainfall is significantly influencing the abundance of small mammals in south-western Australia including Brush-tailed Phascogales (Rhind and Bradley 2002). However, there is uncertainty about how individual small mammal species in southeastern Australia respond to changed rainfall patterns. The aim of this study was to assess any relationship between the abundance of small native mammals and rainfall levels. We investigated the effects of rainfall on the population dynamics of species including the near threatened dasyurid marsupial the Swamp Antechinus (Antechinus minimus) and Pseudomys novaehollandiae (New Holland Mouse), a native rodent which is critically endangered in the state of Victoria, in southern Australia.

Publication Type: Conference Item
Murdoch Affiliation: School of Biological Sciences and Biotechnology
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