You should probably qualify this with location. Countries that have had domestic and wild cats for millennia are mostly unaffected by domestic cats being outsi

You should probably qualify this with location. Countries that have had domestic and wild cats for millennia are mostly unaffected by domestic cats being outside, especially in urban areas where wildlife is overrun by vermin. Yes, there are plenty of examples of cats causing issues, but only in locations where they were introduced and not where they are native. Australia is a good example, as domesticated cats have become a nuisance and bred in the wild. But then you look at what has happened since the cat population was culled, with the many videos of mice on farms. Removing them isn't a perfect solution, as they've been around long enough to become a part of the ecosystem and not just a destructive force. I would also qualify this with; cats should be kept inside whilst in heat. Many of the issues caused by cats are due to owners letting their cats reproduce. Where cats have a good supply of food, naturally they will reproduce up to a balancing point with the available food. Many cat owners are unaware (or just don't care) about cats reproducing and the impact that has. Spaying/neutering is also a viable option if owners don't want to have to lock their cats in during their heat cycle - cats birthing can be traumatic for the mother, so this can be a major benefit. Similarly, male cats will mate with multiple females so neutering is many times more effective than spaying alone.