networkn:
I like cats, we have 2, lovely animals except for the plaintive meowing... It's understandable to your desire to feed cats due to your affection of them, but I don't think it's reasonable to say doing so isn't having an impact or isn't a risk to native life in your area.
Glad you like cats. Like I said, there is also a personal issue involved that I am not prepared to go into. I don't doubt the cats do have an impact. So do lots of other things. What is the lifespan of a sparrow, anyway?