sugar repels birds
I've read about using sugar to repel bird predation repeatedly over the last few years although reviews have been mixed. There's an article in Good Fruit this month that states that several commercial cherry growers are applying 8 pounds of white sugar a week with clear success of a 75% reduction in bird damage. It has also been successful in protecting Honeycrisp apples.
Lack of a sucrose enzyme in the digestive system of birds like robins and starlings leaves these species ill from the sugar and they soon learn to leave fruit alone. It was mentioned that magpies are not bothered.
Olpea, with a peaches ability to hold a lot of spray material I figure you should give this a try. I certainly am going to at cites where I'm spraying anyway.