Professionals tend to favour tracking tunnels over chew cards.
By studying the tracks we are able to gain a lot more information about what’s out there. The trade off is that the learning curve is steeper as we need to learn to identify the tracks. Once again the Predator Free NZ website is the go to place for excellent info.
Most authorities suggest that to give native species a chance we need to keep tracking rates below 5%. So if we put out 20 tracking tunnels for a night we are looking to get prints in only one tunnel (or none). With rats this is hard to stay on top of.