When I worked in the tart cherry breeding program at MSU, we used nets to exclude birds. They are a lot of work to install and we did get a few birds trapped inside every year after making their way in through some small opening. I built a simple frame out of EMT that was easy to set up and take down, and we draped a net over that for a couple of the smaller trees. That prevented the net from getting tangled in the branches. Otherwise, a mix of approaches tends to work best, using shiny things that move in the wind, sounds, etc.

There are several compounds that are applied by spray to reduce commercial crop loss to birds. The research is not extensive or fully consistent, but many growers use the products. The most commonly applied is methyl anthranilate. It can reduce loss in cherries, but its effectiveness is mixed in research studies, depending on a variety of factors. The chemical compound itself occurs naturally in many fruits and biodegrades rapidly, so it should not present notable risk to human or environmental health, when applied according to the label. Also, birds tend to begin eating cherries just before we would normally harvest them, so it is possible that a single spray when they are almost ripe would suffice. That said, I have not evaluated the inactive ingredients added to these products as sold, and those additives can change the safety profile.