Mamaku Point success with trap and cameras


Mamaku Point view

Mamaku Point is a 172 hectare predator free reserve in Rakiura Stewart Island. It contains over 181 native species, with 26 native bird species, including kiwi and kākāriki. Since 2000 it’s been protected by a predator proof fence across the peninsula.

Mamaku Point predator proof fence

The reserve is open to school camps, kiwi spotting tours and other visitors. Coincidentally it is home to two PurePods (PurePods and The Cacophony Project were both started by Grant Ryan, or Bro, as I call him)
Mamaku Point PurePod


Unfortunately animals can get past the predator proof fence at times. This can happen if trees come down on the fence, or more often, around the ends of the fence, particularly at low tide. One end of their fence terminates at the water, the other on the top of a high cliff.

Until recently they would know a cat had got into the reserve when they started to find dead birds. What follows is normally a long process of trying to find the cat, with the aid of trained dogs and trail cameras. This can take anywhere from a couple of days to a couple of months. 

When they catch a cat outside of the fence it's full of rats. When they catch a cat inside the fence it's full of birds.

They have a number of traps around the fence targeting cats including Steve Allen cat traps, Tims, Trapinators, Possum masters, raised leg holds and A12. For rats they have the DOC 150, and 200 and D-rat traps. Despite all of these traps often a cat will ignore them all and progress into the reserve.

Camera locations at Mamaku Point

The first camera - Lee Bay

Lee Bay end of predator proof fence at Mamaku Point

Mamaku Point started out by renting a thermal camera to see how useful it was. Immediately they started to see some animals coming around the fence, mainly rats, but also some cats and the odd penguin. This was useful enough for them to decide to purchase the camera and set it up permanently.

I was fortunate enough to visit the area late last year while on holiday (highly recommend) and saw there was a well worn track that was perfect for one of our traps. They received funding for a high interaction rate trap and second thermal camera.

The second camera

Horseshoe Bay end of predator proof fence

The 2nd camera at Horseshoe Bay terminates at the end of a cliff. This would appear to be much harder for animals to get around.

However the camera has seen large rats and possums make their way around the fence. The video evidence (below) that a possum had gotten around the fence prompted the local ranger, Antony Simpson, to hunt it immediately. He was able to get it on the first night before it got too far into the reserve. This saved considerable time.


The trap

Antony installed the trap and hazing on the path at the Lee Bay end of the fence, on the path most animals appear to take when they come around the fence.
High interaction rate trap at Mamaku Point

High interaction rate trap at Mamaku Point

In just a few weeks he caught a couple of feral cats and a rat. Although this is only two feral cats, this makes a massive difference to some of the endangered birds. Mamaku Point is one of the only places on Rakiura where some of these birds are breeding and it is the time of year when vulnerable chicks are hatching.

You can see the hessian hazing is an integral part of this trap, guiding the animals into the opening. These animals were caught with no bait in the trap. It was placed in the path that the animals were going to be. If you are making a fishing analogy: rather than a hook and bait this is like set netting.

Catching these feral cats also saves Antony a massive amount of time and effort by not having to hunt them in the reserve.

Next steps

The next steps are to:

  1. Install solar power to the cameras at each end of the fence to remove the work required to change the batteries every couple of weeks or so. 
  2. Bring both cameras on line. Each end of the fence is just out of cell phone reception. We have set up a Wi-Fi hotspot near one end of the fence that will reach the camera and hope to do the same with the other end of the fence. This will allow Antony to get real time alerts when animals are detected and respond immediately.

The Cacophony Project has developed a version of this trap that can be activated only when a predator is approaching. This uses a thermal camera running a real time AI system. This means non-targets like penguins can use the path without activating the trap but when a predator follows it they will be caught. 

The Cacophony Project is also working on a new, humane method to automatically eliminate predators. This work is supported by Predator Free 2050.

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