Boat-tailed Grackle

Well, the boat-tailed has an exceptionally long and wide tail and the Common Grackle is generally smaller than the boat-tailed, so I'd also say boat-tailed grackle.

http://greennature.com/gallery/bird-pict...

I'm sure it's a grackle but there are two kinds in Georgia. Boat-tail and Common.

Unfortunately this is the only picture I took. They made a strange noise when they flew short distances. I wasn't sure if it was from air moving through their wings or a vocalization.

can't tell but this looks like a Boat-tailed Grackle