brodifacoum

A resetting toxin device (the “Spitfire”) has been designed that delivers a toxic paste to a rat’s ventral surface when it passes through a tunnel. The rat grooms off the paste and ingests the toxin. The system was assessed in cage trials and one field trial. The purpose of the cage trials was to investigate whether a range of toxins can be delivered by the Spitfire to rats (Rattus rattus and R. norvegicus), namely 0.55% sodium fluoroacetate (1080), 0.2% brodifacoum, 15% cholecalciferol, and 12.5% zinc phosphide.

House mice (Mus musculus) are highly invasive mammals and can cause extensive ecosystem damage on islands where they are the sole mammalian pest species. Capability to eradicate mice has improved in recent years. Mouse eradication has been achieved on large islands where mice cohabit with other rodents and islands where mice are the sole mammalian pest. As the islands targeted for eradication become larger and more challenging, reduced toxic cereal bait application rates can reduce both complexity and cost, and ultimately make currently unachievable operations feasible.

Brown kiwi (Apteryx mantelli) in central Northland have been monitored for up to 32 months of sustained exposure to brodifacoum poison. The cereal baits were placed in bait stations to target brushtail possums (Trichosurus vulpecula). Annual survival of 55 radio-tagged adult kiwi in two poisoned forest patches has been high (95.9%), and similar to that in two nearby unpoisoned forest patches and in the patches before poison was used (95.3%).

Toxins, especially sodium monofluoroacetate (1080) and brodifacoum, are widely used throughout New Zealand for control of introduced mammals that are considered pests. This level of toxin use (not necessarily with these toxins) is unlikely to decline for at least 5-10 years. Ecological consequences derive both from mammal population reduction or eradication, and from using toxins as the control method.