[–] hmimperialtortie Cats. Just cats. 0 points

Yes, I’m all for keeping cats inside - mine have been indoor only for many years, as much for their safety as for the birds’ - but this “alien and invasive” terminology comes across like some “kill all the cats” psychopath. Hello, all domesticated animals can fit that description, and yes, all humans outside Africa.

I don't think most domesticated animals would be considered invasive, just introduced (which I gather is another term for "alien"). Do they blend in or disrupt local ecosystems if they go feral? We're invasive, but I doubt cattle or sheep would be considered anything more than introduced in most places. I'm sure they're on that list somewhere. Biologists catalogue everything.

This reminds me a bit of when I kept referring to "Mytilis edulis, the edible blue mussel", when presenting my honours thesis in geology, and someone thought I was making a joke. Why no, malacologists gather from around the world to decide on official common names.

[–] hmimperialtortie Cats. Just cats. 1 points

Feral horses, brumbies, are definitely invasive in Australia - they are very destructive to the alpine areas because of their hooves. For that matter cattle are very destructive there too, though they’re not feral, they’re run by cattle farmers.

I'm curious. Do the feral horses have predators? Or do they just go where they want? Wait, this is Australia, so probably no natural predators. Maybe people should eat them.

I know cattle that are managed as if they're wild – all bunched up and moving regularly the way they would in the wild with natural predators – can actually be good for the land (depending on the specific land). I've seen videos of a farmer somewhere in the drier parts of Australia using holistic management (and also leaky weirs), and his land is so much greener than his neighbours. But that's not how most ranching is done yet.

And I should add that I wasn't thinking of Australia or NZ at all when I was thinking about livestock (though NZ and cats is another matter). I was thinking about how in places like Europe and North America they fill a niche that was already part of the ecosystem (e.g. bison, aurochs) so they're not breaking it. Sorry to be so down-under-exclusionary. I should remember that some places are very different from where I am.