Trapping, poison, hunting, and fences have all been turned against pests to help prevent the ongoing slaughter of New Zealand birds. However, we know that current trapping methods aren’t cutting it. As part of our experimenting we have had video trail cameras pointing at existing (traditional) traps to measure how well different digital lures work. What has completely surprised us is that as little as 1% of the time that a possum turned up on camera a trap was activated. For our tests we have been using a Good Nature and Timms trap but have rarely actually caught one.
Video 1: A couple of possums having a party around freshly baited traps
It is very possible that we completely suck at setting up traps. However, we have also heard from a few others who have videoed traps that they have also been surprised at how infrequently they catch predators compared to how often they are seen on camera. Most of our footage was in autumn when there was lots of other food around so hopefully the kill percentage will get better in winter.
As a service to anyone interested in trapping we thought we would produce a table that shows how effective different devices are at catching and detecting predators. Many of the numbers are a cumulative guess from experienced trappers but feel free to let us know your evidence of success rates for traps and we will update the table.
The success is defined as the percentage of times the trap is activated for every time the predator is caught on camera.
There will always be a range of results for trapping - eg first time in winter may work better than when there is lots of food around at a different time of the year, or for populations that have become ‘trap wary’. Also the placement of the trap and many other factors could change the effectiveness of traps.
In many ways this is good news - lots of room for improvement! In our model of making traps better we were only assumed that predators were caught on 50% of interactions with the trap rather than 1% .
These results have moved our focus from luring pests at a distance to creating a way to hold a pest in a certain place so a kill could be activated without them having to stick their head in a trap.
Our goal of using automated cameras and AI identification of predators will allow mass experiments with different digital lures and traps to dramatically improve the efficiency of traps. There will be no need for stories and hunches because anyone will be able to try anything and get an accurate measure of how well it works.
So let us know what you think and don't let this stop you using existing traps - it's as good as we have got for now.