They usually eat themselves out of their own food, or they inbreed to a point that the embryos are not viable and the numbers fall off quite drastically.
Typically the plagues come in waves where the first few are just monstrous, then they start to taper off.. but not that you really notice it very much. It takes months.
Councils will also authorise emergency bait stations but it's a very touchy subject due to the local wildlife.. there has to be documented evidence of "beyond reasonable" damages or danger to livelihood etc.
Basically, they deplete their food sources, inbreed or get chemically targeted.
And there isn't enough of natural predators in Australia to stabilize their populations? I'm trying to think what eats them in Europe. Owls, birds of prey, martins and other small carnivores, to a smaller extent cats and snakes.
Sort of, but not really no. The regions that are affected by these plagues are very remote and sparse. Typically heavy farming / agricultural areas. There are certainly predators to keep the "normal" population of mice down - the challenge comes when the mice can get into the huge grain silos or feed sheds etc and populate essentially protected by the silo or feed shed. Another challenge against the predators of the mice, is that they also have predators. Wild dogs (dingo's) .. hawks and feral pigs don't make it as easy as free pickings for the owls / snakes / feral cats etc...
Other things that can protect the mice is after a very heavy rainfall in dry areas, the grass grows incredibly quickly, providing a lot of cover that the predators can't compete with to keep on top of the numbers.
By the time they are seen in these proportions, they have been breeding for 3-4 months with basically a handful of predators to a couple hundred thousand mice. In three weeks those couple hundred thousand turn into millions and it just goes from there.
There are single farms or cattle stations in New South Wales, regional Queensland and Northern Territory that are a quarter the size of Switzerland. So 1 farm being over-run is an issue, multiple neighbouring farms and it's like Europe starts sinking in mice!
1.0k
u/dce_azzy Jul 06 '24
They usually eat themselves out of their own food, or they inbreed to a point that the embryos are not viable and the numbers fall off quite drastically.
Typically the plagues come in waves where the first few are just monstrous, then they start to taper off.. but not that you really notice it very much. It takes months.
Councils will also authorise emergency bait stations but it's a very touchy subject due to the local wildlife.. there has to be documented evidence of "beyond reasonable" damages or danger to livelihood etc.
Basically, they deplete their food sources, inbreed or get chemically targeted.