Predator Free pathways: Knowledge, innovation and improvement

Department of Conservation —  10/03/2020

With the launch of the Predator Free 2050 strategy: ‘Towards a Predator Free New Zealand’, we’re doing a series of blogs about the pathways identified in the strategy which are going to help us get to Predator Free.

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By Michelle Crowell, Biodiversity Threats Manager

I’m Michelle Crowell and I’m responsible for managing the Tools to Market programme, which is about developing a range of new predator control tools and technology.

This is an exciting space to work in, but it’s not without some challenges.

I want to talk about some of the things we’re working on, like long-life rat lures and automated pest detection; as well as some of the difficulties in areas where investing in the development of new solutions is very much needed.

The goal of the Tools to Market programme is to develop a range of new predator control tools and technology which are available to everyone involved in Predator Free 2050. The programme is well underway, with several projects trialling the use of everything from new baits to testing prototype pest detection devices.

Kepler near Luxmore Hut1

Image: Alison Murray; Michelle on the Kepler track near Luxmore Hut, Fiordland

The key thing for you to know is that the Department of Conservation isn’t doing this alone. The Tools to Market programme is all about working with others.

This is a collaborative effort in every way.

Long-life rat lures

One of the projects we have been working on with Wellington UniVentures (formerly Viclink, the commercial arm of Victoria University Wellington) is to bring long-life rat lures to the market to control rats by attracting them to traps.

The problem with traditional lures is that they use foods such as peanut butter which perish within days requiring the lure to be replenished. (This is both costly and time consuming, particularly in remote areas like Fiordland).

Long-life rat lures have been developed by Dr Michael Jackson and colleagues at Wellington UniVentures to deliver a sustained release of chemical compounds attractive to rats over an extended time-period.

It’s an olfactory lure based on the compounds rather than a bait.

Gertrude Valley looking toward Barrier Ridge (002)

Image: Jamie McAulay; The Biodiversity management team at Gertrude Valley, Fiordland National Park

For those of you that aren’t rodent experts, it might be useful at this point to provide a bit of context for rats as a species and the challenges we face in controlling them as predators.  Rats are one of the world’s most damaging pest mammals.  They go where people do — rats arrived in New Zealand alongside both Māori (kiore) and European settlement (ship rat, Norway rat).

Nga Manu Images, Norway Rat

Image: Ngā Manu Images; Norway rat in action

Rats are highly effective predators.

As omnivores, they are pretty flexible when it comes to their food preferences – they eat a wide variety of small animals including native wildlife. They steal bird eggs from nests and kill chicks.

Being omnivores, they exploit the food resources they come across in every environment however, this also poses a problem: how does the foraging, opportunistic rat determine what is safe to eat from what may be poisonous (man-made or natural)?

How rats learn to eat in different phases of life-development is fascinating in itself but the general rule of thumb is, ‘if someone else has eaten it it’s good enough for me’.

They smell foods on the fur, whiskers and especially the breath of other rats, and strongly prefer what those rats have previously eaten.

Rats use each other the way royalty used to employ taste-testers, back in the day. (Not a great job).

Re-creating the relevant chemicals associated with rat breath is a way to lure unsuspecting rats to a trap and does not require the reproduction of the food itself.   In the lures that Wellington UniVentures have developed, the chemical compounds last for up to six months and even better, they are also non-toxic.


Image: Wellington UniVentures; One of the prototype methods for lure delivery over a 6-month period, using controlled-release membrane.

Michael and his team came up with a few ways to put the rat lures into prototypes that could be put to the test in trapping projects run by Friends of Rotoiti, Omori/Kuratau Pest Management Group, Pūkaha Mount Bruce and the Wakatipu Wildlife Trust. A couple of the prototypes by the trappers are pictured here.

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Image: Wellington UniVentures; Dr Michael Jackson with Phil Green from Wakatipu Wildlife Trust at a field trial at Wye Creek outside Queenstown 

No doubt the final product will look quite different – watch this space!

vial with memberan in a wooden trap box

Image: Wellington UniVentures; wooden trap box with prototype lure in vial

Wellington UniVentures are now working with Michael and his team to get from prototype tool, to the market, and more importantly out into the bush.

Automated pest detection

Another of our Tools to Market projects is the PAWS® pest identification sensor pad.

Developed by Lincoln Agritech in collaboration with Boffa Miskell and Red Fern Solutions, the automated PAWS® sensor represents a new generation of technologies for wildlife management, allowing us to detect invading predators in real-time in natural habitats.

The sensor will be able to identify pests such as mice, rats, mustelids and possums, and differentiate them from native species.

It means that ferrets will be identified separately from stoats and weasels, allowing managers to respond with the right traps and strategies.

PAWS with Brent Barrett

Image: Lincoln Agritech; a PAWS® device being laid by Brent Barrett from Boffa Miskell

Historically a lot of time and effort has had to go into checking traps and tracking tunnels in Predator Free areas and this is particularly challenging on some of the less visited islands.

PAWS® will not only save this time and effort but will increase our confidence in biosecurity, both for islands and for Predator Free projects on the mainland.

The development team led by Lincoln Agritech tested the PAWS® sensor in field trials in 2019 and are now further training its algorithms to prepare for larger scale trials in 2020.

In the next round of trials, some sensors will be set up to notify all predator detections back to base in real time.  The project can then move forward to testing the devices on different islands once permissions have been applied for and granted.

At the end of the day …

All in all, I’m pretty thrilled with the progress of these projects so far, and I am even more excited about what can be achieved in the next phases as well as the other upcoming projects that our team will be working on.

I look forward to sending you another instalment in the future as we continue our journey to becoming predator free!

Ngā mihi,


For more about the PF2050 strategy, including a run through of the tools that are going to get us there, visit

One response to Predator Free pathways: Knowledge, innovation and improvement

    Karen Pratt 11/03/2020 at 3:33 pm

    Your ‘Tools to market’ link doesn’t work 🙂