pest inquiry
(stoats)
(stoats)
Intro
Stoats have a significant impact on New Zealand's native bird wildlife wiping out over 40% of the kiwi population. What should be done to mitigate the deleterious effect of stoats in the Bay of Plenty? We think that Using more 1080 and spreading it more throughout New Zealand's bush will help out with New Zealand's native wildlife. If we could do that then New Zealand's native bird wildlife will grow more and more. Stoats are a unique animal because they hunt at night and in the day
The description of stoats
The stoat (muslid) was introduced into New Zealand in 1879 they were brought into new zealand in a group of 500 to cull the rabbit population. But as we know they have spread and spread all around New Zealand and now cause one of the biggest pest problems in New Zealand. Stoats have a reddish brownish fur on its back and a white under belly and a long tail like the weasel. An interesting fact about a stoat is that it can run up to 32 kilometers per hour.
Food Web
A food web is a cycle of the food that the stoats eat and what energy goes into each animal. For example as you see here the vegetation feeds four animals, sheep, mice, rabbits , hares and they eat indigenous fauna. The main predators include cats, ferrets, stoats, weasels and possums. This particular food web contains other animals that prey on the same animals as the stoat.
Apex predator
The stoat is an apex predator which means that nothing hunts to stoat so that means it is a growing population which is a bad thing because stoats eat our native birds and bird eggs. While being an apex predator is it quite easy to kill a stoat if you do it right. Which includes traps poisoning and more. The stoat is an apex predator for many reasons. They are very small animals that are capable of avoiding attacks from other animals, they prey on animals five times their size. They are equivalent to a lion in the Serengeti.
Affect on native animals
The stoat has a very very big effect on our native animals in NZ. The stoat kills our native birds and bird eggs. When we went to our school Michele was talking about one of her friends that had chickens. A stoat had got into their pen and started to eat the chicken alive when it was sitting on her own eggs. The stoat eats a lot of New Zealand's native birds including mohua, kakapo, yellow-crowned kakariki, and rifleman. Stoats can eat a native kakapo that weighs 2 kgs when the stoat only weighs 260 grams a stoat can eat something that is up to 5 times its size.
Why stoats are a pest
Stoats are a pest because they eat native birds and native bird eggs. Stoats are also a pest because they eat a lot more food than what they need to survive. If a stoat has the opportunity to kill a native bird like a kiwi then it will without hesitation. It is estimated that 95% of brown kiwi chicks born in the bush each year do not survive and stoats cause 50% of the deaths. Other dangers attribute that the stoat holds; they can swim for 1.5 kilometers without rest, so any native bird on an island can be in danger of a stoat. Young female stoats are already impregnated when they leave the nest they were born in so even one female stoat can start a whole new population.
Control method 1 - traps
Our first control method is trapping. There are a lot of traps to use for stoats but we have chosen to talk about the 200, the a24, and the doc 250. We will start with the doc 200. The doc 200 is the best trap to use in my and Cody's opinion because there are two doors that the stoat has to get through then it gets trapped. Why I think it is the best is because native birds have to think twice about their decision on going through the next door and also birds don't eat a chicken egg or rabbit jerky. Now we will talk about the a24 trap.the A24 trap in a self reloading trap using a mini gas canister with bait at the top of the trap the stoat goes in from the bottom and the trap detects when the stoat is there, the strikes it skull killing the stoat instantly, the lure for an A24 trap is normally a chocolate mixture with caramel. Now we will talk about the doc 200. The DOC 200 is a manual reloading trap that uses a pressure plate to trigger the system. When the stoat walks off on the platform it triggers the swing arm to let go of the tension of the spring which is connected to the metal grate that kills it with force. The one bad thing about trapping it can take time for the stoat to come to the trap and get killed.
Control method 2 - 1080
Me and Cody have agreed on 1080 as our best control method because it states in the DOC website that 1080 has been dyed green to deter birds and also baits are scented with a cinnamon lure to attract possums rats and stoats but not birds. Helicopter flight paths are guided and logged using a GPS to ensure accurate and constant delivery. What does 1080 do? 1080 puts the consumer pest into a seizure. There were 44 aerial 1080 operations in 2019 covering 918,000 hectares of land. Today there are 10.1 million hectares of land that are a forest in New Zealand and 8 million of those are native bush. So 7,082,000 hectares of land in New Zealand were not covered by 1080 which is a lot of land that native bird population is going down and down.
Control method 3 - Hunting.
The Hunting method of killing and controlling stoats is not the most effective way to kill a stoat. Why is hunting not a good method for killing stoats is because it is hard to use a rifle bullet to see a stoat and if you are using a shotgun the chances of hitting a stoat depends on the distance of the stoat. And for hunting a stoat you will have to have at least 10 people in a 1km radius. So hunting is going to be the least effective way to eradicate stoats.
Best control method
Sam and I decided that 1080 will be our best control method because is the past few years the creators of 1080 have made it more environmental friendly by changing the colour so the native bird of New Zealand do not get atracted by the poison. It is confermed that any targeted pest that consumes 1080 poisin will die in the next 1-2 days. The cost of 1080 is a better choice againt trapping and hunting. This is why we chose 1080.
PMI
traps(a24, DOC)
poisons(1080)
hunting with guns
cost
3
3
1
animals killed
3
1
4
efficient
3
1
5
people involved
1
1
1
effect on environment
1
3
Total
11
9
14
This graph on the PMI sheet explains the effects on the environment, people involved,cost, animals killed, efficiency and the lowest score wins the best way to eradicate stoats.
Works Cited
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“//.” // - Wikipedia, https://www.orc.govt.nz/managing-our-environment/pest-hub/animals/stoats. Accessed 26 May 2022.
Brockie, Bob. “Story: Introduced animal pests.” Te Ara, 24 September 2007, https://teara.govt.nz/en/introduced-animal-pests. Accessed 26 May 2022.
“11 pest trapping tips from New Zealand experts + how to catch pests that are killing your chickens.” thisNZlife, https://thisnzlife.co.nz/11-pest-trapping-tips-from-new-zealand-experts-how-to-catch-pests-that-are-killing-your-chickens/. Accessed 26 May 2022.
Heatley, Dave. “Productivity Commission | A stoat trappers' guide to elimination.” New Zealand Productivity Commission, 5 May 2020, https://www.productivity.govt.nz/pandemicblog/a-stoat-trappers-guide-to-elimination/. Accessed 26 May 2022.
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“Stoat (Mustela erminea) - British Mammals.” Woodland Trust, https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/stoat/. Accessed 26 May 2022.
“Stoat - Pest control hub.” Northland Regional Council, https://www.nrc.govt.nz/environment/weed-and-pest-control/pest-control-hub/?pwsystem=true&pwid=60. Accessed 26 May 2022.
“Stoat » Pest Detective.” Pest Detective, https://www.pestdetective.org.nz/culprits/stoat/. Accessed 26 May 2022.
“STOATS 1. Description of the problem.” Convention on Biological Diversity, https://www.cbd.int/doc/case-studies/ais/cs-ais-nz-stoats-en.pdf. Accessed 26 May 2022.
“Stoat - Southland Pest Hub.” Southland Pest Hub, https://pesthub.es.govt.nz/?pwsystem=true&pwid=437&sort=alpha. Accessed 26 May 2022.
“Stoats: Pests.” Department of Conservation, https://www.doc.govt.nz/nature/pests-and-threats/animal-pests/stoats/. Accessed 26 May 2022.