Indicator description

Why is it indicative

What does the data show

Data

Acknowledgment

Indicator description

Population trends for the common brushtail possum (Trichosurus vulpecular)

Why is it indicative

The changes in population numbers of brushtail possums provide an important indicator for helping to determine the impacts of harvesting, culling and recreational take-off; and the potential impacts of the species on tree health.

What does the data show

• Possum (Trichosurus vulpecular) densities are highest in the low rainfall districts of central and south-east Tasmania. These areas also correspond to the main distribution of tree decline in the State. Even though the relationship between tree decline and possum numbers is broad the number of possums maybe playing a secondary role in degrading the health of trees already suffering from decline.
   

Data

Possums occur throughout Tasmania. Their numbers vary according to habitat type. For example, they are abundant in eucalypt forest and woodland (typical of eastern Tasmania) and are much less common in the temperate rainforest - buttongrass vegetation typical of western Tasmania (Rounsevell et. al. 1991 - cited in Neyland 1996).

The Parks and Wildlife Service have been conducting spotlight surveys of possums since 1975, which provide an indication of the relative numbers of possums throughout the State. Useful regional information is only available post-1985. Prior to this, sample sizes are too small to allow a regional breakdown.

Acknowledgment

State of the Environment - Tasmanian Indicator