Mustelid Summit: Bruce Harrison and Emma Whitton

Park rangers Bruce Harrison and Emma Whitton from Shakespear Open Sanctuary attended the Mustelid Summit to share their success in dealing with a stoat incursion in their pest-free sanctuary north of Auckland. It took a truck load of ingenuity and true Number 8 wire mentality, but pest-free status has now been restored to the sanctuary and Emma and Bruce kindly shared with the passionate group of trappers just how they managed to do it.

Shakespear Open Sanctuary sits at the eastern end of the Whangaparāoa Peninsula, and when viewed on a map it looks a little like a stingray, trying to swim out towards Tiritiri Matangi Island. The 500-hectare sanctuary receives about 700,000 visitors a year and also hosts operations for the Department of Defence and Watercare, as well as a campground. The sanctuary is initially protected by a predator-proof fence that runs along the isthmus at the top of the stingray’s tail – though Bruce warns that this fence can be a bit ‘leaky’!

It's likely through this leaky fence that a female stoat wandered in March of 2020. When the stoat was first spotted, the team used a dog trained in finding stoat scat to help them plot a map. Wero the Hero (‘wero’ means challenge) was the right dog for the job, helping them to draw a scat map with his amazing nose. 

Once the scat map was completed, cameras were placed where scats had been spotted, so the team could get a closer look at what was happening. While Wero told them where the stoats were, the cameras told them what they were doing. Once they could see the pathways the stoats were taking on the cameras, they could move their traps into these paths. 

One thing Emma and Bruce learned is that stoats love to play, and love to balance on things. So they created stoat playgrounds! These were rows of traps covered with branches and forest debris. They created an environment to draw stoats in as stoats love searching crevices, and the environment attracted skinks which stoats love to snack on. 

Bruce describes watching the trail cams after setting up playgrounds to catch elusive stoats as ‘must-see TV’. At times they would even jump in the car to go down and get the fresh catch, can then use that to attract more stoats. 

When going for elimination you must get really crafty, so Bruce and Emma moved away from traditional box shapes and began to innovate using shapes that nature provided – in naturally forming crevices, or between large rocks or in rock walls (with everything kept safe for birds and people).  They also started to use their existing tools differently – such as setting traps in trees. They noticed that stoats were seeing the traps, so they started spray painting the DOC200s with camo paint. They would leave them out for a month so the smell goes, and cover up the plates with a sprinkle of sand or bush debris so it feels like the ground the stoat was already walking on. 

At one stage they set up a chicken coop in the bush with traps around it. This was a great success as the chickens were smelly and fresh and noisy which attracted the stoats and they even started laying eggs again! Much time was also spent utilising stoat bedding as a lure. Ever creative Emma and Bruce even asked the zoo for their large animals’ bedding. Anything novel is good is stoats want to investigate.

Eventually, all these creative tricks caught a female stoat they named Princess Munch. DNA showed that was the founder of this intruder population. By keeping Princess Munch and using her scats on the traps they managed to catch many more of her ancestors. By February 2022, less than two years after Princess Munch had burst through that leaky fence, the final stoat had been caught and Shakespear Regional Park was declared stoat free once more.