Kia Pākiki Canterbury – pest control and Predator Free
Professor James Ross works at Lincoln University’s Department of Pest-Management and Wildlife Conservation, where he collaborates with Zero Invasive Predators to study the best ways of controlling the numbers of invasive pests like possums and rats.
Kia Pākiki Canterbury – pest control and Predator Free
In this Kia Pākiki Canterbury podcast, Science Communicator Tom Goulter and co-host Associate Professor Adrian Paterson from Lincoln University interview Professor James Ross from Lincoln University.
Select here to view video transcript and copyright information.
James says he started this mahi when big leaps were just starting to be made, in terms of what technology was in use and what results were being delivered. “Helicopters and bait buckets, early GPS technology,” remembers James, “was pretty exciting.”
Rodents had just been successfully removed from Motu Ihupuku Campbell Island. “There were some pretty cool things that were starting to happen around that time, and I think it was that enthusiasm … that drew me to that.” He cites other stories from the era – Old Blue, the Chatham Island Robin credited with saving the species and the eradication of predators on Breaksea Island and Kapiti Island. “There was always going to be a point where we ran out of those offshore islands,” says James, which led to the question, “can we do something similar on the mainland? And that’s what’s kept me involved and interested.”
James continues to work with the Predator Free 2050 initiative, “They’re motivated and keen, and passionate about what they’re doing and very keen to keep pushing and advancing on what they’ve done.”
Towards Predator-Free Banks Peninsula
He’s working on a research trial in Horomaka Banks Peninsula where 10,000 hectares has been laid out with traps and infrastructure. “Now we’re moving to the how do we defend that area? How do we stop new animals from coming into that area?” Possums are the big target for much of this mahi, but for other nearby operations, hedgehogs are far more of a concern.
European hedgehog
The European hedgehog (Erinaceus europaeus) is a pest in New Zealand. They were introduced in 1870 to eat slugs, snails and grubs. Unfortunately, they also eat native birds and their eggs, lizards and insects. Hedgehogs have no natural predators here.
That surprises many people, who find hedgehogs cute, but the little animals are a major pest in Aotearoa New Zealand and can have serious effects on native bird populations. Larger animals like cats may predate adult birds, but in terms of stealing eggs out of nests and hampering bird population growth or recovery, hedgehogs are a major culprit. Nor are they just a suburban pest. Hedgehogs in Aotearoa live everywhere from the banks of braided rivers up to alpine zones. “I think people underestimate how much of an impact they have. They’re almost like little vacuum cleaners. We don’t know a lot about their biology,” says James. “We find it difficult to monitor them … And the old adage is … if you can’t monitor them, you can’t manage them.”
Studying predators to eradicate them
Zero Invasive Predators isn’t just about eradicating predators. It also wants to study the animals to better target them. That’s what the 2 hectare predator research enclosure is for. “It’s got a predator fence around it that’s turned inside out,” James explains. “It prevents animals getting out as opposed to animals getting in.”
This provides an enclosed space where pest species can be studied for things like what lures will work best in traps. “We’ve been looking at combinations of audio, video and social lures,” James says. Possum urine, possum poo, possum tails and bedding material have all been trialled for their scent. Even the scent trails left by other animals are tested for their efficacy in luring possums into a cage trap.
The technology used in the fight against predators has come a long way, says James. “10 years ago, we were using chew cards and tracking tunnels, and then it went to trail cameras.” These are equipped with passive infrared sensors to detect movement and can be used as a non-invasive way of trying to monitor where animals are. Nowadays, thermal cameras are used, but the next stage, which is on the way, is AI-equipped, self-reporting cameras that can identify targets themselves and report back instantly.
AI is useful in this context because it can help traps to distinguish between target and non-target species, but it needs a lot of training. “There’s citizen science opportunity there too,” says James, “There’s a lot of people that love to go on sites and identify photos for you … I don’t think we should undercount the role of citizen science.”
Ethics and sustainability
A lot of mahi goes into making sure animals are being controlled, which in many cases means killed off, in as humane a method as possible. James says there are many factors at play here, from time to death to the Three Rs of animal ethics. “Some people get quite angry about having to go through ethics to do their research, but I see it as quite an important part of it,” he says. “If we’re wanting to publish this or also to put this out there where it’s going to be seen by the public, we need to be sure that we cover all of those bases.”
Three Rs poster
The Three Rs – replacement, reduction and refinement – are principles intended to minimise the harm and suffering of animals within laboratory settings.
Download a PDF version here.
Another area in which there’s always work to do is sustainability. James has been working with a PhD student on reducing plastic use in pest-monitoring mahi. “Her passion was, well, we’re trying to get rid of single-use plastic everywhere else in New Zealand, why aren’t we doing it in the conservation estate?”
He says he was initially sceptical of how big a problem this was, but “actually realised that 15–20% of all the plastic we put out to do monitoring stays in the environment. And if we’re doing monitoring four times a year, we’re talking about kilograms of microplastics,” James says. “Are there better or other options that we could use that work just as well but then don’t persist?” His team have been working on innovations like biodegradable chew cards and tracking tunnels.
“Maybe there’s that one little moment with Predator Free that might come at some point,” says James, “that ends up being the big thing takes us to the next level.”
Related content
Can we make New Zealand pest-free? – introduction: a series of lesson plans focusing on students becoming actively involved in contributing to a pest-free New Zealand.
Scientists using ‘fake news’ to stop predators killing endangered birds: scientists protecting endangered shorebirds by spreading misinformation among predators.
Find-A-Pest: a citizen science app that allows anyone to report and identify pest species.
Invasive animals in cities: efforts are underway to reduce predators in bush areas, but cities are a major target too.
1080 and pest control – a timeline: traces the introduction of pest mammal species to New Zealand, the use of 1080 for pest control and how advances in science and technology have improved how we use it.
Alternatives to 1080: hunting, trapping and poisons are the three most commonly used methods of mammalian pest control in New Zealand.
The Science Learning Hub Pokapū Akoranga Pūtaiao has two Pinterest boards with related content – Predator Free NZ and PESTS!
Activity ideas
Cats, especially feral cats, are also pests. Use these activities to initiate discussions about pest control of animals we value – for example, cats or deer and other sport animals.
Useful links
Zero Invasive Predators: Check out the work being done across the whenua by ZIP.
Predator Free NZ has news on predator-control initiatives and tips for getting involved.
Zealandia has many educational resources. For advice or assistance in implementing this programme, please contact the Zealandia Education team, education@visitzealandia.com.
Find out more about local and global conservation efforts by WWF, the World Wildlife Fund.
If you want to get involved at an individual or community level, check out the Predator Free New Zealand Trust.
Pest Free Banks Peninsula lets you report sightings of pest animals in the Banks Peninsula area where James has been working.
Acknowledgement
This interview was excerpted from an episode of Kia Pākiki Canterbury, a monthly podcast about science, technology and humanities presented by the Canterbury branch of the Royal Society Te Apārangi.
Kia Pākiki logo
Kia Pākiki Canterbury is a monthly podcast about science, technology and the humanities presented by the Canterbury branch of the Royal Society Te Apārangi.
