ZIP began investigating the potential of low-height predator fencing as a barrier to possums, rats and stoats at our Lincoln predator behaviour facility in 2017.

Predator fences are typically capped with rolled steel, which is costly to install and maintain, and limits the scale at which they are able to be used. As a result, ZIP has also been investigating alternative capping materials to prevent target predators from climbing or jumping over fences.

In June 2019, our friends at Predator Free Wellington (PF Wellington) asked us to test the efficacy of a low height predator fence for ship rats, capped with high-density polyethylene (HDPE) pipe. The PF Wellington team is currently carrying out a predator removal operation on the  Miramar Peninsula. They intend to protect the peninsula against reinvasion by ship rats using a network of low-height predator fences, traps and bait stations.

The methods, results and conclusions of this project, along with our recommendations to PF Wellington, are available here.

We found that 15 of the 16 wild-caught ship rats tested in this trial (i.e. 94% of the ship rats tested) were unable to cross an 800mm high, 12mm x 12mm mesh fence, constructed with a 110mm diameter HDPE pipe cap.