This brings into play the whole introduction of non native fauna and Flora. I realise cats were probably not deliberately introduced being common inhabitants of sailing ships in back in the day.
Cane toads ,Foxes and of course all the other introduced species. All have changed our landscape, Mostly for the worse.
One looming on the Horizon is the intention we are told to introduce The Carp Herpes Virus to Australia.
Very Very Dangerous when countries round the world cannot rid their ecosystems of the Virus. Which is worse The Cure or the Disease?
It's like the tens of millions dollars spent here trying to rid the country of Fire Ants which seems to have failed drastically.
In the 60's we trapped an shot rabbits for $$$$$ and a farmer in the Adelaide Hills asked us to bump off a couple of feral cats that were dragging down newborn lambs.
We trapped one and it demolished about 1m radius of blackberries and got the other about 3 hours later,, shot while watching us. Both had front teeth longer than 25mm. Like foxes they appeared to be killing for fun not just a feed.
__________________
Why is it so? Professor Julius Sumner Miller, a profound influence on my life, who explained science to us on TV in the 60's.
Seen and shot a few feral cats most of which were domestic cat size, but some can grow to be monsters. Shot one that was almost as big as a small kelpie one time. Was preying on the lambs.
We identified that cats were responsible for death of about 20% of our lambs, until we up the anti. One day in a crop whilst harvesting I saw a cat carrying an 80kg wether. no dragging. Stood a bit over 18 inches at shoulder.
Solved 2 problems in one go. Trapped and destroyed 28 parrots that were in plague proportion, inserted strictine into breast and tied to fence with wire. After 6 months we did not see any cats on a nights spotlighting. Not very legal but we were permitted to destroy the parrots (had permit for 200 at a time) but not to use as bait. Kept up with a bit of baiting and it surprising how many ground birds and small mammals started to be observed around the farm. Obviously not only lambs that got killed.
There are still some farmers that don't want innocent foxes and cats destroyed. I can assure you I never destroyed an innocent one.