Trap and relocate. It works. Same with lethal trapping. You'd think that you're just bailing the ocean, but squirrels are territorial. If you remove some from a location, others won't move in until the next year. But be careful, killing squirrels is not legal in Austin city limits. Yeah, they're just too cute. I relocate about ten every year in the spring, and I have no problems after that. Takes some effort.

We have barred owls aplenty, and they do virtually nothing to squirrels. A squirrel is VASTLY too big for a screech owl. A nesting box for the kind of owls you need is about as large as a compact refrigerator. Hawks will help, but you need a lot of them, and the only way to attract them is to have lots of rodents.

Thanks very much for the comments. I have used a live trap, but perhaps I need live trapS. The overpopulation point is spot on. Too large for most owls and sleeping while the coyotes roam.

Trap and relocate will certainly help the problem, but you should know that nearly all of the relocated animals will die as a result. As you said, squirrels (and most wild animals) are very territorial. So, you are dropping them into an unfamiliar place that is probably already occupied by other animals.

In general, that is true about relocation and survival. If you remove an animal and drop it off in a random place, it will likely not survive. But I live along an urban creek. I trap, and release a few miles down on the same urban creek. They move from one locale to an identical one. So food and nesting is not an issue. Making friends is another.

As it turns out, I drop them all off in the same place, so most of the other squirrels they run into are probably siblings!

Oh, for the live trap, you need good bait. Peanut butter. Works all the time.

The people where you drop them off at do not appreciate your gift. Take them to the animal center and let them kill them if you are unable to do it yourself. I live in a relatively squirrel free area. We have a few black rock squirrels. That's it . I would like to keep it that way; so don't bring them here. If you are going through the problem of removing them from your house; don't make them someone else's problem. I think that is an ethical problem. As they say NIMBY.

The Texas Administrative Code technically addresses this concern by requiring anyone transporting live trapped nuisance squirrels to carry written permission from the owner of the drop site property. I've heard differing things about how this applies to particular parks and other public lands. So beyond the ethics, the legal intent is clear that you shouldn't move squirrels to private property without the owner's okay.

The challenge with live trapping on our small urban lot is that once a squirrel has been caught, the rest will avoid it for 4 to 6 months even when the trap is moved to new locations with fresh peanut butter bait. Catching and moving only two or three a year doesn't make much of a dent in our area.

That's correct. Texas regulations are that you can't drop them off on people's property without their permission. So no lack of appreciation is extended. I drop them off on public land.

Animal centers in the city will not kill squirrels. No one in the city will.

https://library.municode.com/tx/austin/codes/code_of_ordinances?nodeId=TIT3ANRE_CH3-2REAN_ART1GERE_S3-2-4HUTRWIAN

Not so about trap avoidance, at least for me. I catch squirrels in the same trap several times a week. In the course of a spring, I get about a dozen in the same trap, with the trap mainly in the same place. Maybe my squirrels are just dumber than yours. That makes a big dent in the local population. Before I start trapping, I'll go outside and see three or four of them at a time. By the time I'm done, I hardly see any. As I said above, rodents move around seasonally, so if you get rid of squirrels in the area of your house, they won't repopulate that area until the next year.

Maybe my squirrels are just dumber than yours.

I doubt that, but only guessing there may be some differences in how well/long a squirrel can be seen or heard by their peers fussing about being stuck in a live trap. They didn't seem to build up similar aversion to the lethal traps our neighbor used on the other side of the fence. We've done most of our trapping in the side yard veggie garden area which is in clear view and earshot of our neighbors' huge red oak and pecan that are their favorite nesting and hangout trees in our part of the block. I check our live trap at least twice a day when set, so a trapped squirrel could have 3 or 4 hours to make a warning racket for their onlooking and nearby friends.

Interesting. My trapped squirrels don't make a racket. They just bounce around in the trap. Some get vocally upset as they are being transported. But most don't.