This year I have been to several U-Pick cherry orchards in Brentwood, CA (about 20-30 minutes ride from my place). With acres of trees covered with ripe sweet cherries I didn’t see a single bird or any visible/audible protection devices (Air Scarecrows, reflective bands, sirens, etc.). Finally, I asked one of the owners what they do for bird control. He told me that they spray the trees with a mix of honey and vinegar. I don’t know what proportions are in the mix and whether this is the only method they use. I tried googling this method and only found descriptions of mixes that use hot peppers and vinegar.