A mouse plague is ravaging through several states in Australia, causing widespread damage to crops, damage to buildings and infrastructure. A prison had to be evacuated. Why is there a mouse plaque? What can be done to resolve the mouse plague, aside from the obvious pesticide? What can be done to prevent it from happening again?
In: Earth Science
It’s happening because mice are non-native and have few natural predators. What can be done? Nothing.
because they killed most the feral and stray cats off instead of trapping, neutering, and releasing them back into their environment
The mouse plague has been caused by a “perfect storm” of optimal weather conditions for breeding and the end of the 2017 to 2019 drought.
The mice first appeared in the spring of 2020 when farmers were harvesting a bumper crop.
There was plenty of grain in the paddocks and in storage for the mice to eat, as well as fewer predators, which died during the drought.
https://www.abc.net.au/news/rural/2021-06-11/mouse-plague-australia-why-it-happens-and-can-it-be-stopped/100195082
Related question. Does anyone know the species?
I heard a couple of people say that they’re a native species, but I for the life of me find any proof either way. A lot of articles imply that they’re introduced house mice, but I don’t think I’ve ever seen the species name published.
TLDR:Environment around farms trashed by drought, fire, flood and farm practices.
Mice, a rapidly breeding invasive species, survived and moved into these areas and had no competition and lots of food as rains came.
Farmers didn’t realize that this was a perfect storm and didn’t do anything different (more baiting/changes to storage and harvest practices).
Mice started invading farms in December 2020.
Smaller mouse plagues happen regularly so everyone is still chilled (except the farmers who were getting hit)
March 2021 the mouse are out of control and have completely overwhelmed baiting on many farms. Farmers started freaking out and asking for help.
Government slow to react for various reasons (politics, covid, rural v city divide)
Videos started going viral in April and May. News (local and international) makes big noise about cities being overwhelmed.
Government finally reacts and offers millions of dollars in support and is trying to get a banned poison approved for emergency use…
All that can really be done is continue baiting, trapping and improve storage of grain and wait for the the balance to return…but this is costly for farmers and not guaranteed to succeed…
There is also talk of bio controls like tailored viruses that kill or sterilize the mice but that will be years away…
Long version:
Mice are an invasive species to Australia that breed rapidly and can thrive around humans. Most local animals are not super adapted to eating mice and can’t survive around humans. At “normal” times mice would be a problem but 2020/2021 was not a “normal” time.
A very long drought and the massive fires and then floods killed lots of the local animals that ate or competed with mice.
Now the mice also suffered. But remember they can live around humans and enough mice made it through the bad times by hanging around the houses and farms.
When the rains came the wild land around farms started to recover and plants began to grow creating lots of food. Some of the mice left the farms and houses and moved into these areas where there was a lot of food and nothing to fight with or eat the mice.
Through the Autumn and Winter of 2020 the population was growing unseen in the wilds and everything seemed okay. But when spring came around even more food became available and the mouse population exploded.
At around the same time Australian farmers were taking in some of the best harvests on record and processing and storing them. Many farmers store grains in MASSIVE plastic bags or leave them open and rely on trapping and baiting to prevent mouse populations from exploding…they did this at there usual levels not realizing what was going on in the waste land around the farms…
As Summer came (December 2020) and water and food resources reduced in the wild the thousands of mice went in search of food and found the grain. Through the summer farmers were doing extreme baiting but the mice kept coming…the many surviving mice now gorged themselves on the stored grain and the surging population was further boosted to the plague levels…
Individual farmers and communities began sounding alarm bells around February 2021…but localized mouse plagues are actually pretty common in Australia and so these warnings were ignored by government.
Things continued to grow and the viral videos started coming out at the end of March and into April…the farmers were like “we’re serious there is a major problem we need financial help and scientific support.
Politics and the distraction of covid definitely played a role here: they had received bailouts and support from the government during the drought and fire…there are fewer farmers than there are city dwellers so provincial/state level politicians pay less attention to farmers [at least according to the farmers]…things like that…kept the local government from paying too much attention.
But by around 12 May 2020 things were so crazy that they had to pay attention with local and international news running stories about mouse plagues overrunning the cities…so the government had to start paying attention…there were also some local elections around this time that could harm the party in charge of New South Wales (the state most impacted).
The government went from offering very little support to offering 50 million dollars for baiting which was then increased to 100 million (in the form of rebates on zinc phosphide bait purchases). And they also tried (and are still trying) to get a banned rat poison authorized for emergency use.
Bromadiolone (the poison in question) was put forward as a quick fix that would act like “Napalm” and cut through the mouse population. But almost everyone, including a lot of farmers think this is a terrible idea…as it will napalm the environment along with the mice…
Basically the way out is increased baiting and improved storage facilities and a coordinated response where hot zones receive specialist support and help…but this will take months and will cost farmers millions in expenses, lost crop and lost planting seasons.
[I made an explainer video that may help…](https://youtu.be/02FW-nP6NKE)
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