WWF's Conservation Innovation Awards

Gathering votes
Gathering votes

Compost and catch, spreading the predator free movement.

To better equip people in eradicating predators by using their home composting system as a base for luring and eliminating threats to urban and suburban wildlife. Then to engage people in the predator free movement by designing a trapping system that notifies them when a predator has been caught and allows them to easily link their data to sites that manage and track predator populations.

What conservation problem are you trying to solve?

The predator free movement and government goals are moving New Zealand towards becoming a predator free Nation. But rats and mice as well as other urban predators are still a major threat to native flora and fauna.

Food waste is becoming a huge global problem from the extra emissions that food waste creates rotting in landfills to the associated cost of having to grow and distribute unnecessary food. This is leading to consumers being more thoughtful in what they buy and there has also been an increase in the amount of home composting

Effective composting is a much better way to get rid of food waste as decaying food is probably the single largest source of material in a landfill that creates methane.  But the increase in home composting is creating a safe and prosperous environment for urban predators to nest and reproduce.

How are you going to solve this conservation problem?

We already know that rats and other urban predators are attracted to home composting systems, no matter how secure that claim to be. And while setting external traps around the composting area is good we also know that they still want to get into the composting bin as it is a dark and safe environment for them nest and feed in.  

By designing a simple and cheap composting bin that has an integrated tunnel and predator trap we can make it easy for predators to enter the bin but only in a way that ends with them in the trap.

We also need to get the average person willing and engaged in managing the trapping system. The trap is designed to be externally set and upon activation ‘kill and contain’. While a base line unit could have a simple version of the trap there is benefit in adding a higher tech version which notifies the user through a simple app that the trap has been activated and then has a way where they can notify a larger predator management site.

What makes your idea new and unique?

By piggy backing on the increased uptake of home composting and designing and integrating a user focused trap we can engage more people in becoming part of the predator free movement. Then by connecting the trap with a simple smartphone application that receives notifications of when the trap has been activated and allows the user to report to and be part of a larger community we can add to the goal of a predator free New Zealand.

Who will use your idea, and how will they benefit?

People that already compost will benefit by knowing that while their food waste will be attracting urban predators it will no longer be a safe place for them to be. 

People that have disregarded composting because of the advantages it gives to urban predators will be able to start and know that their food waste is now being dealt with in a more effective way.

The predator free movement will have a wider section of the community involved in pest control and also a larger set of data to track predator populations.

What tasks or activities do you need investment for? How would you spend a $25,000 grant?

  • Accelerate the design and prototyping of the best method for efficiently and accurately eliminating urban predators in an integrated compost / trapping system.
  • Production of final working prototypes that can be used in a large study comparing compost trapping and traditional trapping in urban and suburban environments.
  • Design a simple smartphone or web based app that notifies users of activated traps
  • Link data obtained from individual users into existing databases of community predator trapping.  

Are you a New Zealand citizen or resident?


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List five other ideas posted in the challenge that excite you. Why?

Thermal Imaging and Ur-bins

Both of these are trying to solve the same problem as my concept and I’m excited about my idea so it makes sense I’d like these too. I’ve got some pretty good reseach on how rats get in and out of compost bins but I’d love to get my hands on Geralds imaging system to get hard data. Hannah (Ur-bins) has also put out the call for CAD/CNC/Engineering help which is my area so I have offered her a hand.


The Baleen Filter

As an design engineer I specify a lot of plastics and work really hard to design and specify with recycled and renewably sourced materials. Unfortunately this is not the norm in my industry and it’s great to see innovative solutions which restrict the harm these materials can do.


Seawater electrolysis

It just seems like a good idea and sounds like the grant money would be go along way to proving the technology in our environment


Guardians of Zealandia

My kids would love this - we live next to otari wilton bush in wellington and are constantly going to the talks and other things they put on. I see the engagement they get from well crafted activities and would love to see that same energy in more kids.


How could you improve your idea?

The process and pressure (good pressure) of having this idea in the WWF conservation innovation awards has really focused the idea from a loose concept to what I believe is a targeted solution to an obvious problem.


The presentation I uploaded the other day should outline the changes / design work done since entering the competition. But the main points and learnings are:


- Target the product at the 10000’s of existing compost bins in our country.

- Design for vertical composting bins, the worst type for harboring urban pests.

- Make the unit fit a wide range of existing vertical compost bins.

- Besides the pest problem, when done right composting is a virtue so do not impede on the composting process.

- Design a low cost base model which uses a lwo cost pressure pad trap.

- Design a higher value automatic product (Good Nature has already been contacted and initial meeting setup).

edited on Oct 12, 2017 by James Prier

Brent Beaven Sep 30, 2017

Hi. I like the concept as compost bins are so productive that they prevent rats going into traps set near-by. Few questions: It seems you are looking to have a fully integrated unit, but perhaps there is potential to have the trap part available for retrofitting to existing compost bins? Price per unit will likely be an issue as buying poison or traps to set in an existing compost bin is quite a cheap option....have you considered what will make your unit more attractive? There are a huge number of apps being created and existing traps....do we need more, or is there opportunity to integrate existing technology?

Good luck,



James Prier Oct 1, 2017

Hi Brent, thanks for the feedback

Nothing is really too fleshed out just yet, most of my design work recently has been based around efficient composting and getting more homes (and apartments) better managing their food waste - which is my real passion. The Composting trap idea was prompted by comments from the local ‘predator free’ groups and I’ve just run with it.

The designs that I have been been working on so far seem to fit into three areas

- Fully integrated composting bin, tunnel and trap.
- Composting bin with tunnel and space to put a trap
- Retrofit kit that adds into to most compost bins

I'm not sold on any idea just yet as they all have their merits and drawbacks and will appeal to different people.

With my own compost bin I’ve tried some variations on traps in tunnels / not in tunnels, on top of the bin / in the middle and at the bottom. The best success I’ve had so far is when the tunnel and trap are at the very bottom of the bin with the entrance right at the bin wall. The biggest thing so far is that I haven’t been baiting traps just leaving them in the system and letting the compost be the bait

So I’ve got a few goals in this,
- Reduce food waste
- Get more people composting (and in a better way)
- Get a wider range of people catching pets.

What i’m also trying to consider is why people don’t already set traps
- They don't think it’s an issue in their area
- Are too squeamish and don’t want to touch or even see a dead rat etc.
- Don’t want to ‘waste time’ checking trap that hasn’t caught anything yet
- Don’t want to have to bait traps.
- Feel as if it is a fruitless pursuit / are they actually making a difference

If anyone knows of existing research please link me to it.


Brent Beaven Oct 2, 2017

Thanks for the extra detail - that adds a lot more context. There is some research underway, but no results available yet. That's aid, I think there is a social movement underway that will help drive change. The more people who are trapping together, then the scale will make a difference.


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James Prier Oct 1, 2017

As far as apps and notifications, my expertise is in product design and not software so if there is existing technology that is working well then great. A quick google and some advice from others suggests trap.nz and eco node as options to look into - any other suggestions welcome

The really low fi version of this could be as simple as a flag that pops up on top of the compost bin when a trap has been activated. Users can look out their window and see if they need to go and reset.


Brent Beaven Oct 2, 2017

I think the biggest value is if your system is able to integrate its communication with a broad range of apps and networks. Like you said, a simple flag could also be very effective.


James Prier Oct 11, 2017

Hopefully you’ve seen the update to my concept where I’m focusing more on retrofitting current compost bins, they already exist so let’s turn them from a nuisance to a virtue. Anyway you’ll also note that I’ve dropped the App and data side of the idea – I think there is more than enough scope in the idea and like you’ve said heaps of existing technology that does that job already.

The low cost version of the product will accommodate a standard pressure pad trap and a visual indicator (flag) is still an option. I’ve also just started talking to the team at Good Nature to see how my design can be changed or modified to accommodate there current technology.


View all replies (2)

Hannah Smith Oct 3, 2017

Sorry James. My heart sank when I saw your entry. Obviously great minds think alike☺. I've been really baffled that this idea hasn't been put into practice before now. If you win the prize I'd be happy to contribute what I've learnt over the last few months. Best wishes, Hannah


James Prier Oct 3, 2017

Hey Hannah, don't be sorry it's great that you came with a similar idea. From what I've found using a composting system to attract rats and then get them inside or on exit is far and away better than external traps.

From prototypes I have made and seeing some of the comments that I am getting on this forum and others I think my product might be going down the route of retrofitting existing compost systems with a tunnel/trap system.

Anyway you'll get my vote and i'll post another idea for you system on your page (you get more points for comments)


Brent Beaven Oct 6, 2017

Hi James.
We are one week out from judging and you have the basis of a great idea. As I said to Hannah, as Predator Free NZ moves more and more into urban communities, then this becomes more important.
I would suggest you either spend more time clarifying what is different about your design from Hannah's, or look to join together??
At the moment, you outline the idea and in the comments outline that you are partway through design. I recommend you get more specific to make it easy for the judges. Perhaps take one of your designs and elaborate on it a bit more? Highlight your thinking about trap integration and so forth.
Will check in again mid-week. Good luck.


James Prier Oct 10, 2017

Hi Brent, thanks for the feedback.

I've got a little bit more to tidy up but will have a presentation of the idea with more detail and my process so far uploaded tomorrow.


Gerald Dickinson Oct 7, 2017

Hi James,
Building rat trap into compost heap is a great idea. I have this issue at home and need a better solution for it.
I am not sure of trap design you are working on but one idea is to have vertical trap on side of compost (similar to down piping on house) This creates the only access route in and out of compost. Once rat frequents path then introduce trapping mechanism into top end of down pipe. Ideally a self resetting trap similar to good natures A24 using compressed air.
Trap kills animal and drops to bottom of down pipe, disposal either by human or scavenged by cat. It is possible to have some electronic counter to determine rat activity.
Would this be a trapping unit that can be bought and added or would be a compost incorporated unit. Ideally a separate unit would be easier to maintain and move.


James Prier Oct 10, 2017

Hi Gerald, all good points

I'll be posting more information tomorrow but essentially the design as it stands will be a retrofit to existing compost bins.

Funny you mentioned down pipe, all my prototypes so far have used down pipe in some fashion (lots of cut up Marley box section used) to help me determine the best location of trapping rats in exiting compost bins.

As far as a automatic traps I really want to be able to keep costs down and so far have only been using pressure pad traps. In saying that there is no reason why there cant be two versions so have started a conversation with the guys from Good Nature. We'll see if there is any benefit in incorporating a version of their technology into my design (or changing my design to incorporate their tech).



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James Prier Oct 11, 2017

Since posting this idea and get lot of good feedback both here, in other forums and talking to others I have revisited the concept and refined it down to one idea.


The link above will take you to a presentation which shows my process and thinking so far and details our the proposed product. But in essence the product is a replacement for a vertical composting bin lid that turns the bin from a place that feeds and protects rats and other pests to one that lures and catches them.

There are thousands of these bins in our urban environments and rather than replace them all the goal would be to turn all of them into traps by offering a cheap and easy to use product.


James Prier Oct 11, 2017

Presentation as a PDF incase the link doesnt work


Brent Beaven Oct 12, 2017

Hi James.
Well done in getting this nailed down more explicitly. Good luck.


Becky Wilson Oct 13, 2017

The idea has been progressed to the next milestone