A couple of years back, I caught birds pecking at my tomatoes. I had no idea that they would do that until then.
A lady at church told me to set out a couple of pans of water near the area, that the birds were probably thirsty. I did it and it seemed to help.
We had some problems with squirrels and rabbits until a stray cat took up residence under a shed and we have seen fewer of the nuisance animals since. I have ambivalent feelings about cats but so far I've not caught any bothering the garden, they are also helpful with any snake problem as mentioned earlier.
We have a feral cat that catches a squirrel now and then. I need to plant some basil, and spray with some pepper spray, and maybe hang some computer disks around.
I have also read that they don’t like to smell soap and avoid coffee grounds.