Geographic Patterns of Genetic-Variation in Brushtail Possums Trichosurus vulpecula and Implications for Pest-Control
- School of Biological Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand
- Forest Research Institute, P.O. Box 31-011, Christchurch, New Zealand
- Present address: Science Directorate, Department of Conservation, P.O. Box 10420, Wellington, New Zealand
- Present address: Advocacy and Extension Directorate, Department of Conservation, P.O. Box 10420, Wellington, New Zealand
Two morphological types of brushtail possum (Trichosurus vulpecula) were introduced to New Zealand: smaller, grey possums from mainland southeastern Australia, and larger, black possums from Tasmania. Analysis of patterns of allozyme variation and allele frequencies of present-day possum populations in New Zealand and southeastern Australia indicates that populations comprised predominantly of black possums remain genetically similar to possums in Tasmania, whereas predominantly grey populations are genetically closer to Victorian and New South Wales possums. The distribution of possums in New Zealand can be accounted for at least partly by selection of stock types with respect to climate. Genetic differences between populations may have important implications for the control of possums, because Tasmanian possums have a greater resistance than mainland sotheastern Australian possums to 1080 poison (sodium monofluoroacetate), which is commonly used to control possums in New Zealand.