My cat won't' leave my bird alone?

My cat Sy won't leave my parakeet PJ alone. I live in an apartment so we keep the parakeet up high on top of the fridge. Sy sees this as her personal challenge. She'll jump on the counter and onto the top shelves to get to him. We scold her by yelling, "No sy! Get down!" And we'll squirt her with a water bottle. She gets down but not even 5 minutes later she's back up there! We've been having this problem for awhile now. We have 2 other cats and they don't seem to care about the bird at all. I can leave the other cats alone with him in the same room and not worry about it. So what can I do to nip this problem in the bud and have her leave the bird alone before the poor thing has a heart attack. Oh and for the record sy is a year and a half and the other cats are 7 and we've had the bird 5 years. Thank you! Sorry so long!