Here is an example of ship rat reinvasion after a successful 1080 op (est. 97% knockdown). The exclusion zones around huts and a campground (where no 1080 is permitted) are a primary source for reinvasion/ repopulation of the wider valley. Op date March 2024.
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Nice maps! I’m assuming that the blue dots are the catches. Are the yellow polygons and dots the exclusion zones?
Yeh, that’s right. We’re looking to undertake rat control in these zones concurrently with future 1080 ops.
That was a fascinating look of the value of 1080. Hugely worrying to see how quickly the population re establishes. 2050 Predator free NZ remains a diminishing hope!
But if those exclusion zones had the same knockdown, the picture would look very different. There are lessons here we should all should learn from. 1080 ops have come a long way in the last 20 yrs, I’m optimistic they’ll keep improving and issues like this will be sorted.
Hi the std accepted is that after a 1080 operation ship rats will be back to pre operation levels in about 6 months, rat numbers can come back hard and fast, remember when you knock down rats to say 2% RTI there is an increasing amount of food that is not now being eaten by ship rats, so as rat numbers start coming back there is a super abundance of food so rat numbers take off.
yes I agree 1080 Ops have improved but that is mostly in reducing the kgs required per hectare , while 1080 is the best we have it has a similar problem to say Cyanide it is naturally occuring so some animals have a natural aversion, plus just like humans you can’t expect everyone to scoff down the same food.
I also have to agree 2050 has been a disapointment fairly much from day one, for the hundreds of millions already spent I don’t see much to help the people on the ground at a price point people can afford and they still don’t have a plan. They would have been better off to say concentrate on possums which are the easiest then apply what they learnt to other animals.
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Ship rat recovery is also very dependent on weather and food availability. Remember with 1080 you have likely taken out their predators and other competition for food. The Kaharoa Kokako Trust routinely assess RTI at 6 and 12 weeks following our spring pest ops. To give you an idea of ship rat increases (all bait presented in bait stations):
2021 (1080) 11% post-op (yes a poor result) at 12 weeks 21%. 2023 PIndone 16% post op & at 12 weeks 38%. Then we halved the distance between bait stations to 50m. 2024 1080 0%. 12 weeks 10%. 2025 Pindone Post op 0% 12 weeks 24%.
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