They were first introduced to New Zealand in Riverton, Southland in the 1830s by Captain J. Howell, yet this release proved unsuccessful. The first successful introduction happened at the same place in 1858 by C. Basstian. In the following year and between 1890 and 1900 possums were released in large numbers in both the North and South Island by the region acclimatisation societies. As a result of the increasing recognition of the negative effects of possums on the native forest releases later than 1922 were mainly undertaken illegally.
Possum have very broad habitat requirements and may be found in a diverse range of habitats with rainfall from 350 mm to >8000 mm/year and altitudes up to 2400 m. They mainly feed on leaves although at times bark, buds, flowers, fruits fungi and invertebrates can be a large proportion of their diet as well.
Possums selectively browse certain favoured palatable plant species (particularly podocarps such as totara and pahautea) and this can lead to extensive defoliation of the canopy and changes to vegetation composition. Possums also prey on invertebrates and the young and eggs of birds which may have secondary effects on the vegetation due to changes in ecosystem processes.
For more information see*:
- Possum (Wikipedia)
- Possum (DOC website)
- Possums - Te Ara Encyclopedia of New Zealand
- Possums - Kiwi Conservation Club
- Possums in New Zealand - Landcare Research NZ
*The Network is not responsible for the content of external internet sites