Jeez, I’ve heard it all when supposedly sane people start talking about cats “murdering” birds. They don’t murder, they kill. They kill because they’re predators and nature made them pretty efficient ones. I like them as pets but feral ones are a problem, they’re going to do what nature designed them to do. I don’t doubt that they reduce the number of birds because most of them are pretty good at killing.
I live in the country and years ago we had three cats. A feral tomcat showed up one day and my wife started feeding it. It would run the other cats off of the food and after a few days one of our cats came up lame, it was limping because of its hind leg. I told my wife I needed to shoot the feral but she didn’t want it shot. The next day a second one of our cats was limping and the day after that the first lame one disappeared never to be seen again. My wife’s attitude changed to “shoot that effing thing!!!” which is what I should have done day one. It quickly soaked up a .22 LR bullet.
Cats are what they are and have to be controlled whether that be by keeping them inside or through other means. Not all outdoor cats are uncontrollable but if they get too destructive sometimes you’ve got to step in an take care of it.
I agree that ferals are a huge problem; and there's no obligation to try to capture them to collar them when they are a danger to so many species, including humans. I can see why you had to dispatch the one that harmed your dear kitties.
We used to live in a dense city in a rowhouse. One day a feral alley cat who looked almost identical to our tabby housecat got in through the second-story cat door (within an alcove on a rooftop deck) in the near-dawn hour. Somehow he had scaled a brick wall to get up there, entered the second floor and made his way to the top floor bedrooms, forgetting the pathway by which he got in. He jumped up on my child's windowsill, attracted by the outdoor air, and began growling and clawing at the screen to try to get out. My kid was too scared to get out of bed and called to me that there was a strange cat in his room. I told him to hide under the comforter and ran down two flights to open a can of tuna and run back up two flights to lure it with the tuna downstairs and out the door. No way was I going to touch that thing -- it might have clawed me or given me a disease.
It turned into a good lesson with my kid -- although that cat looked almost identical to our cat, he had been raised with different "values," privileges, and training -- and hence could not behave with safety around civilized people.
That said, I think the cat collar article above is directed at the owners of housecats. Or, as the housecats call them, "the help."