No Grapes

I have an arbor over the front sidewalk and 3 yrs ago I (Momma Lobo and I) decided to plant grapes. One concord and a variety called Mars. 2 yr old plants in the ground. 1st year, nothing much happened. Last year a whole lotta bunches but did not mature. This year started out as a bumper crop. Grew good, grapes getting bigger, starting to get sweet. BAM!!!!! Mockingbirds out the wazoo. Little beggars aren't even scared of us. Scarecrows (long sleeved shirts on hanger), Pie plates and various things that move and make noise hung all over the arbor. Looks like a hardware store. Takes them about 5 minutes to get used to each addition. Covered best as possible with window screen. Still find a way in. Dead grapes covering the sidewalk. Walked out on the porch this morning with a cup of coffee and could see 3 of them pecking away. Glanced over at me and kept on eating. Waving my arms and " Shoo!!!" Looked like a covey of quail flushing outta the vines. Grapes almost gone. Guess I'm not gonna get any this year either.