The grackle is the one with the iridescent head, the one flying is a red-winged blackbird. The great variety of blackbirds in Northern Illinois is awfully fun. Grackles fly in large packs and are very smart and efficient at emptying feeders. They also attract a lot of brown-headed cowbirds, which lay their eggs in the grackles nests, and the grackles raise the cowbird babies -- opportunism at its best.
If you look closely at the full-sized original, you can see the grackle has a seed in its mouth.