Overview
Introduced as a valuable furbearer from 1831 onwards, the Australian opossum spread rapidly in both islands and is still expanding its range into the remote parts of Fiordland and Northland. Numerous liberations persisted until 1921. Initially they were strictly protected, and until the 1940's only harvested under a strict licensing system. Since then the destructive effect on native vegetation has been realised - they browse on the canopy and destroy entire trees, preferentially eliminating each species.
Possums or Opossums?
The term ‘possum’ for the introduced Australian opossum (Trichosurus) seems to have been first used scientifically in Australia around 1934 to emphasise the difference from the American opossum (Didelphis), however, although ‘possum’ is used extensively a colloquial term in Australia and New Zealand, it is also well established as in the United States.
In New Zealand ‘opossum’ is used in legislation and in scientific papers, with some exceptions where 'possum' has been used. Either term is correct, so for best usage we should perhaps follow Captain James Cook who used the term ‘possum’ in reference to the Australian species, but only sometimes omitted the ‘O’.