Bird - Scare Flash Tape etc.
Bird Scare Flash Tape: Mylar ribbon that is red on one side and silver on the other. When attached to food crop plants just prior to the fruit maturing, this product and other similar products gives good bird repellency. The ribbon looks like fire moving in the wind. Same company sells the Birdscare Octopus. Birdbusters has many products listed with online sellers (and a search on bird flash tape will offer up lots of brands in the search results).
A listener tip offers a different approach: small cotton bags that are slipped over the forming fruit and the birds go away. There doesn't seem to be one particular brand, but a search on "Small cotton drawstring bags" offers a lot of results (this link goes to the bulk offerings).
"The bags are 4 X 6 and weigh nothing so no chance of bag dragging fruit off of tree. The bag slips over individual fruit and drawstring secures bag to fruit. Once the fruit is bagged the birds are gone." —W. Snavely