Aha! I figured out who/what has been knicking all my blueberries before I can get them myself. My primary suspect was a bird but then I thought perhaps a rabbit... Neither of those -- two little chipmunks! I witnessed them this morning climbing into the bush, up the branches and out towards the ends (a delicate balancing act), and snatching the riper berries into their mouths before climbing down and scampering off to their secret stash site. They are just light enough that the thin branches support them and they wiggle their tails carefully as counter-balances. I may have to try and capture them on video.