Hi, we have recently purchased some AT220s and before we put them out we’d like to know what the recommended spacing is. The same as trapinators or because they are more effective can we put them further apart? Any advice? Cheers H
We have a number of these also. The answer to question as always sits around objectives of target species and level of control.
Our original trap layout was for low level background suppression of possum and sited for wild cat catch. We have found the more sparse layout to use a lot of resources to service for little true on ground gain though did get five cats early on and certainly a lot of rats and possums!
Our new objectives are more around intensive possum control and in some areas rats so will be tightening the layout to reflect this. Locally another group are 200x200 for high level possum control. Others I have heard at 350.
We have a mosaic of bush and farmland which changes our layout also.
Good luck
Hi, as a start point, I’d suggest reading the Bay Bush Action report here: http://www.baybushaction.org.nz/Docs/Bay%20Bush%20Action%20AT220%20Field%20Trial%20Report.pdf. It’s an awesome study on their experience with the AT220. They achieved possum eradication with a trap density of two per hectare. We’ve achieved near-eradicaton with 150 traps spread over 450 hectares… so one per three hectares (on average). We’re upping our fleet to 200 traps (100 AT220 and 100 AT520) so that will get us to one trap per 2.25 hectares… which we’re hoping will be enough.
Given the cost of the AT220, I suspect most organisations will need to make do with way less than this. Two valid approaches. If you have a defensible perimeter, deploy around that first… they’re great to limit incursion. Beyond that, I’d suggest deploying evenly across the area, starting with a low density and then densifying. Any density of AT220 is going to have a significant and very fast result.
The AT520 gives the opportunity to be more agile in trap placement… monitor the trap interactions… if there are none, move the trap… that way you’re trapping where the predators are!
One last suggestion. TrapSim Plus (https://trapsimplus.landcareresearch.co.nz/) is a staggeringly awesome tool for running trap scenarios at different densities. It’s easy to use and produces easy-to-interpret results - great for funding applications. It’s one of those hidden gems of NZ Conservation… it deserves way more visibility!
I hope that helps
I started with only a few AT220 traps and didn’t initial set them up with any spacing but rather in areas with the most sign. This seemed to be really effective so as I have added more to my area I have followed the same principle. Pushing the trapped area further and further out. I have backed this up with checking areas with chew cards and the 2040 thermal camera and freed up traps to move.
Thanks for your replies, it’s always helpful to know what works for others. Cheers
Helen