Kararehe Kino - Animal Pest Research Issue 33
In this issue
Editorial: Research towards achieving a predator-free New Zealand
New Zealand’s mission to eradicate rats, stoats (shorthand for all mustelids) and possums from New Zealand by 2050 has raised eyebrows, enthralled or angered people and kickstarted a number of new predator control and eradication projects across the country. Whatever your perspective, the bar has been set very high, and consequently many people have engaged in the thinking, planning and on-the-ground action to achieve this national goal.
Building the Predator-Free 2050 Limited Research Strategy for 2020-2024
PF 2050 was established with two aims: (1) to supercharge local and regional efforts to scale up predator suppression and eradication, working closely with community groups and regional and city councils, and (2) to focus research efforts to achieve a breakthrough science solution capable of eradicating at least one small mammal predator by 2025.
Predator-free New Zealand: how will we know?
As part of our national bid for a predator-free New Zealand by 2050, numerous predator eradication projects continue to pop up around the country. Yet the question remains: how will we know when we have successfully eradicated the last predator?
Use of cameras and artificial intelligence to monitor wildlife
Motion-triggered cameras (‘camera traps’) can be an effective tool for monitoring wildlife, especially animals that are rare or secretive. Although camera traps can collect large volumes of useful data, processing the images can be time-consuming and expensive. For example, cameras are often triggered by non-target animals (e.g. livestock) or by vegetation moving in the wind, creating many thousands of superfluous images. Until recently these images have been processed manually by human annotators, but developments in the field of artificial intelligence are set to revolutionise camera trapping.
Knowing when to walk away: tools for proving eradication success
A common feature of all the current Predator Free New Zealand 2050 projects is attempts at regional-scale eradication of at least one species of pest. For example, Hawke’s Bay Regional Council (HBRC) is currently eradicating possums from Mahia Peninsula, while Predator Free Wellington is targeting mustelids and rats on Miramar Peninsula.
Modelling complex eradication scenarios: predicting possum eradication success for Whakatipu Māhia – Predator Free Māhia
Predator Free 2050 has the goal of eradicating possums, rats, and mustelids from New Zealand by 2050. Outside conservation areas, responsibility for pest management often falls on local government agencies, and many regional councils have adopted the Predator Free 2050 goal, establishing pest eradication projects alongside partner organisations.
Lessons from ecosanctuaries – already predator free!
The vision to be predator free by 2050 has been greatly enhanced by successful achievements in previous decades of numerous smaller predator-free visions in diverse ecosanctuaries around New Zealand.
Camera trapping and occupancy models to measure residual stoat populations
In pest control, it isn’t the number of animals you remove that matters. It’s the number that remain. Monitoring the level of these residual pests in controlled areas is vital to the optimisation of trapping regimes and to determine whether each programme is meeting its pest reduction goals. In order to do this, conservation managers need reliable, accurate, and timely measurements of the abundance of their target species.
Bait switching: Pathway to possum freedom using 1080?
Since about 2005, Graham Nugent, Bruce Warburton and others have been trying to locally eliminate possums using aerial 1080 baiting. Back then, Residual Trap Catch Indices (RTCIs, a measure of possum relative abundance) of zero were sometimes recorded after 1080 operations. The initial work was funded by New Zealand’s bovine tuberculosis (TB) management agency (now called OSPRI) and sought to determine whether it was feasible to reliably achieve 100% kills of possums within an area. For OSPRI, that would have immediately eliminated TB infection in possums. Once TB freedom had been achieved, management would no longer need to maintain zero possum density (by preventing reinvasion). The term ‘local elimination’ was therefore coined to distinguish the ‘temporary reduction to zero density for TB freedom’ from true eradication, which requires not only achieving zero density but also preventing any reinvasion.
