Trichosurus vulpecula

In New Zealand, ship rats (Rattus rattus) have been implicated in many extinctions, declines, and range contractions of native birds, so ship rats are an important target of predator control. The outcomes of ship rat control operations are difficult to predict due to other factors which affect rat populations including altitude, Nothofagus seedfall, and control of other mammalian pests, particularly brushtail possums (Trichosurus vulpecula) and stoats (Mustela erminea).

Invasive mammalian pests threaten biodiversity globally across a diverse range of habitats. The unique combination of resource subsidies and disturbance in cities can provide favourable conditions for invasion. Recent interest in urban biodiversity enhancement has increased the demand for effective urban pest control, but efforts are often hampered by a lack of understanding of the ecology of urban invasive mammals.

Strategies for defending large tracts of land from mammalian pest incursion are urgently needed. We report on a study investigating whether brushtail possum (Trichosurus vulpecula) range expansion into a controlled area was restricted by a watercourse. The true left of the Orongorongo River valley was treated with 1080 poison baits, and a 250 ha area bordering the river on the true right was excluded from treatment. Nontoxic cereal bait containing pyranine biomarker was sown repeatedly over half of the excluded area for nine weeks after poisoning.

Brushtail possums (Trichosurus vulpecula) present an ongoing threat to New Zealand’s environment and economy. Research into additional control techniques is vital to ensure that a variety of efficient tools are available to help achieve population suppression. Encapsulated sodium nitrite (NaNO2) has been developed in New Zealand as a new toxin for possum and feral pig (Sus scrofa) control. Its toxic effects at high doses are mediated through the induction of methaemoglobinaemia, a condition in which the carrying capacity of oxygen in red blood cells is reduced.

Banana passionfruit (Passiflora tripartita var. mollissima) is a noxious vine that is invasive in forest patches in coastal regions throughout New Zealand. We investigated the dispersal mechanisms that facilitate its spread in the Marlborough Sounds. To find out which animals act as dispersers, we monitored tagged fruits in the field. Fruits were removed quickly after ripening.

The Australian brushtail possum Trichosurus vulpecula is a pervasive marsupial pest of New Zealand. Impacting on the native flora and fauna and the nation’s livestock industry as a vector of bovine tuberculosis, T. vulpecula is a priority for control and eventual eradication. Possum control at present relies on conventional trapping and poisoning methods. Efficient allocation of control depends on accurate quantification of abundance, which could be achieved with the implementation of non-invasive sampling schemes.