Do rats serve a useful (for us) purpose there? If not, can we release a rat specific poison or is that impossible without harming the entire ecosystem?
The guys who do this professionally/successfully in a sparsely populated place with everyone helping and the advantage that rats can't survive outdoors don't think it's possible in cities.
Big problems with poison: Rats are harder than you think to poison, they're both sceptical of new food and adapted to survive lots of poisons Evolution will work against you and select rats that don't eat or digest your new poison You will poison lots of things you don't intend to (wild animals, pets, humans).
You can imagine an IOT solution in 50 years though (coordinating web of mechanical cats/ferrets with amazing smell/sight that just never stop hunting).
It's hard to imagine a public education campaign like this working today:
> Posters and brochures on rat control were widely distributed; displays were presented at local fairs, picnics and rodeos; and talks were presented to schools, 4-H clubs, agricultural societies, Chambers of Commerce and to just about anyone who would listen.
...let alone with this level of dedication from the educators:
> At a series of meetings with members of Indigenous communities, an Alberta Agriculture staff member ate warfarin-treated rolled oats while discussing rat control and the physiological effects of warfarin. He was able to effectively demonstrate the relative safety of warfarin to concerned community members, and they were able to move forward together.
It took about a decade for the program to work, but it did work:
> The number of known rat infestations in the border area increased rapidly from one in 1950 to 573 in 1955, and the numbers varied between 394 and 637 during 1956 to 1959. After 1959, the numbers of infestations dropped dramatically (Figure 3 [showing # rat infestations in Alberta hovering between 0 and 4 since 2000]). Hence, almost 10 years passed before an accumulation of training, experience and public education brought the rat problem firmly in hand.
And finally, rat control seems to be a point of genuine public pride. Something about regularly trumpeting government success in media is weird to me, but they seem to have earned it, and it's useful to keep people appreciative and aware.
> The discovery of a rat in Edmonton or Calgary receives full media coverage. In addition, the success of the program is reported by provincial or national media three or four times a year, and this success serves as a reminder to the residents that rat control is still an important program in Alberta.
Great link!
Animals bunch around places where there is food. And the hard part is if you have food these animals generally multiply well enough to eat that food.
In India its common to see street dogs, because food littering. Some times they take away the dogs, but they repopulate again in months/years. And in places where they don't litter you will see there are no dogs.
> can we release a rat specific poison or is that impossible without harming the entire ecosystem?
"Eradication" is a bit of a misnomer because it is not possible to actually eliminate rats from a city. The goal is to keep them from getting out of control. However bad a rat problem is, it can get much worse if unchecked.
These programs use a combination of public education, on-demand services (poison, burrow-treatments), and other interventions like city codes for proper garbage containers/handling etc.
It’s been done before: https://www.thecanadianencyclopedia.ca/en/article/rat-contro...
Modern sewer systems separate storm runoff from sanitary sewers, and try to keep the sanitary sewers sealed off from animals. It's hard to change the infrastructure under a bustling city though, so most major cities tend to have the sewers they were built with, or whatever was retrofitted when it became apparent that sewage in the streets was worse than the expense of building a sewer system. However, rats are clever and do occasionally find their way in and around modern sewers as well.
"Urban areas in the UK cover around 16,000 square kilometres. If we distribute the rats evenly across the urban areas, which is clearly unlikely but necessary for the calculation, each rat has a rather spacious 5,000 square metres to roam around in.
Assuming you're standing at a given spot in an urban area you would be at most 164ft (50m) away."
Not sure how they maintain a population if they remain 100m away from each other
...elaborate?
Oh, and I always wondered what all the fuss was about with the Japanese macaque monkeys and their cultural transmission stunt. I saw one rat getting inventive with the drinking water tap, beginning to take water with cupped paws and use it for washing her fur. Others picked up on that habit, and yes, it spanned generations.
200,000 still seems low. I wonder what fraction of the rat population lives outside the sewers.