Answer: Wow! Six hundred blueberry bushes! With so many I suspect they're planted in neat rows for easy maintenance and harvest. If so, your best option would be to build a simple structure so you can enclose each row with bird netting. There are some mylar streamers that are touted to scare birds away, but a more secure method would be to build frames so you can drape bird netting over the top. Be sure to anchor the ends of the netting to the ground so birds can't get into the enclosure and get stuck.
Good luck with your project!
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