Possums, stoats, and rats introduced into previously mammal-free New Zealand (NZ) seriously impact our native flora and fauna. As a result, considerable research effort has focused on their control, with excellent success in the eradication of mammals from offshore islands. Unfortunately, we have run out of defendable, non-human occupied islands and the current focus is the NZ mainland, with a new government goal called Predator Free NZ 2050. In 2010, the Centre for Wildlife Management and Conservation started a research programme investigating new control and monitoring tools that could be used on the NZ mainland. More recently (2015) a privately funded research entity called Zero Invasive Predators Ltd (ZIP; both based at Lincoln University) was established with the goal of developing technologies to remove predators from large mainland areas and then defending them from reinvasion. ZIP has since demonstrated that a modified delivery technique for aerial 1080 can achieve near eradication of rodents and possums at two study sites. ZIP was then able to defend both sites in the short term using a virtual barrier of traps and/or geographical features such as rivers. The CWMC (with the Taranaki Mounga Project) investigated the use of self-resetting traps as a ground-based rodent control tool. The traps were unable to maintain average rodent tracking rates below 5% (avg. 11.5%) without regular trap servicing. To maintain low rodent numbers required a trap service every 3-4 months and this is not cost effective compared with alternatives. To improve detection rates the CWMC (with Cacophony Project) have shown that that thermal cameras are 3.6 times more sensitive than trail cameras for detecting possums. These cameras will quickly find survivors and/or reinvading animals using species recognition software combined with wireless communication. As Predator Free NZ 2050 scales up, more pest control will take place near urbanised areas. As such, the next focus should be the development of control tools with higher social acceptance. Surveys indicate the preferred control options are trapping and species-specific toxins. What this feedback highlights is that future research needs to reduce the cost of trapping so that it is affordable for community groups. In addition to this, funding is required for the registration of species-specific toxins, which have higher public acceptance.

Introduced rats continue to have a major impact on biodiversity around the world, and improved control techniques are required to avoid further extinctions. We are trialing re-setting toxin-delivery systems (Spitfires) targeting a range of predators, including rats. The rat Spitfire works by firing 800 mg of a toxic paste onto the belly of the rat as it passes through a tunnel; the device then resets. When the rats groom the paste from their fur, they ingest the toxin. Each Spitfire is capable of approximately 100 doses and is fitted with a counter and a delay mechanism. We trialed 0.55% 1080 paste in the Spitfire and 15 of 15 wild Norway rats and 14 of 15 black rats died. Further trials are planned with a range of toxins to allow flexibility of use. Resetting devices that are expected to work for long periods without being serviced also require long-life lures. Preliminary trials showed urine and scats from female Norway rats were attractive to both male and female Norway rats. The volatile components from these and further trials will be identified to aid in developing a long-life lure. The long-term, effective control of introduced rats will require a range of toxins with different modes of action, a number of different delivery systems, and long-life lures.