Common brushtail possum in New Zealand

The common brushtail possum (Trichosurus vulpecula) was introduced from Australia to New Zealand, where it has become invasive and a major agricultural and conservation pest.

)[1] European settlers aiming to establish a wild source for food and fibre and fur pelts for clothing introduced the common brushtail possum from Australia (from Victorian and Tasmanian populations)[2] to New Zealand in the 1850s.

An article in Nature in 1870 warned of the dangers, as did farmers and fruit growers, but some academics supported introduction and the Department of Tourist and Health Resorts was still introducing possums at Rotorua in the 1910s.

[7] Possums are vectors of bovine tuberculosis (Mycobacterium bovis), which is a major threat to the dairy, beef, and deer farming industries.

The Biosecurity Act 1993, which established a national pest management strategy, is the legislation behind control of the disease in New Zealand.

For example, at Hohotaka, in New Zealand's central North Island, control work from 1988 to 1994 achieved a sustained mean reduction of 87.5% in the density of TB‐infected possums.

Possums selectively browse native vegetation causing particular damage to broadleaved trees, notably Metrosideros species including rātā.

The predation of bird eggs and chicks has led them to be referred to as "reluctant folivores" in that they eat foliage to survive but prefer other foods.

Trapping and cyanide are generally used by individual hunters as pest control or fur harvesting, while the Department of Conservation, Animal Health Board (AHB) and regional councils use 1080, which can have damaging effects on the surrounding ecosystem [17] to target larger areas.

Almost half (13.3 million hectares) of New Zealand's vegetated land is under some form of possum control, either for conservation reasons, or to reduce the spread of bovine tuberculosis.

The principal of one of the schools said that the contest helped pupils to engage with the outdoors and had also included education about humane methods of possum control.