copy paste from my reply.

we winter in Mexico. Across the street from us was a grackle nesting tree. Just at dusk hundreds of noisy grackles would come in. Long tailed for the bird watchers in the group. They were so noisy we could not talk when we were outside. Well we could be no one could lhear you. They sell super load fire crackers here. Tried that and they would fly off but return shortly. Someone said to get a laser pointer and just hit them with that. Bought one. Paid about 50 pesos for it. With a battery in it. I hit them with it and they would fly off. Kept hitting them until the tree was empty. Next night about half as many birds. It took about 4 or 5 days and we had no more grackles. And they did not come back. 6 mpnths later still no grackles.