Definitely unethical. Domestic cats are already a huge problem for wild bird populations. Why would you want to intentionally make that problem even worse?
You can’t guarantee that only “pest” birds (which still may be native, protected species) will visit your birdbath, or that they won’t carry some illness or parasite to pass on to your cat.
This is impossible to guarantee or control for. Birds migrate, you never know who might make a pitstop at your feeder. I've spotted birds that were so far off their normal range it created a buzz in the local birding community. There's a non-zero chance something endangered or at least very rare could stop by your feeder.
If you're worried about making sure your cat gets enough stimulation there are a lot of articles and tips on things you can do that require little effort on your part (like, even a cardboard box full of crumpled paper can do the job).
Cats that don't know any better can live inside just fine. But I adopted a cat from the shelter that was only allowed to go to a place where he can go outside.
And he REALLY wanted to go outside. Usually you have to keep them inside for at least 6 weeks to accomodate before you allow them outside. He escaped through a tiny bathroom window after 2 weeks. And he came back the next morning wondering why I was stressed out.
Since then I let him outside. Since then, he also became a lot more chill inside. No whirlstorm on my bed at 4 in the morning, no attacking my feet out of boredom, and he generally seems a lot calmer.
Keeping him inside would drive both him and me crazy. So do we have to euthanise all cats like him? Cause locking them up inside is just cruel.
I mean the cats can get enough of their predatory instincts out by play fighting or playing with toys. You can alternatively just use a laser pointer and treats with them instead without affecting the ecosystem or killing birds just tryna live like everybody else
Cats eat birds. You are punishing your cat by getting only a bird bath and not spreading heaps of birdseed around too to attract birds and squirrels for prey. Go for it, cats will thank you. Think of their purring, their adoring eyes. Be sure to put camoflagued and comfortable ambush sites in close reach of the killing grounds. Cheers.
In the winter growing up we had a big ol tomcat and he would get the winter blues when feet and feet of snow would fall, so we'd get a 5 gallon bucket, punch a hole at the base at one side and fill it with birdseed so it would pour out slowly and set it up against the snowbank. We dug a little cat hole in the snowbank that faced it and laid a warm blanket in there for him to sit and watch and hunt the birds and squirrels. We loved that old tomcat, I still have a painting I did of him. Mom would pick and dry flowers and put them in his bed under the layers of old clothes and he would sleep on it near the wood stove and dream of spring. Cats spend only a short time with us and we owe it to them to do anything possible to make their lives more joyous and fulfilling. Thank you, stranger, may you have many happy years with your cats.