If talking with your neighbour didn’t help, or perhaps you’re not comfortable talking to your neighbour about this, I do have some suggestions for you. However, there isn’t one magical solution that works for all cats. What works well on one cat may not work at all on another.
Keep your bird feeders farther than ‘pouncing’ distance from dense shrubbery or other places where cats can hide; typically about three metres.
Provide shelter beyond this distance (more than three metres) to help birds hide from predators. By using native plants, you’ll not only provide them with shelter for hiding, but also with food sources and nesting areas.
Don’t use low feeders or ground feeders as this can make it easy for cats to take birds.
Clean up any spilled seed from the ground. A bird on the ground is an easy target for cats.
If a cat is climbing your bird feeder pole, you can make it more difficult for the cat by:
Using a metal pole
Attaching plastic bottles around the pole
Using a squirrel baffle or a downward opening cone to thwart the cat’s efforts
Cats don’t like the smell of citrus. Strategically placing orange and lemon peelings may help!
Cats don't like to walk on bristly surfaces. You can:
Place branches in a crisscross style or wooden lattice can be used
If your property edges are thick with bushes you can line the bushes with prickly branches like old raspberry canes
Lay down plastic carpet runners, the ones with the little spikes on the bottom, with the spikey side up.
By implementing a few of these suggestions, your backyard birds should be a little safer from your neighbour’s cat.