Each spring before they begin to mate, blackbirds descend on my yard in large groups. Some years it's a handful of red-winged blackbirds, and one year I had a whole gang of various different types including the red-wings, cowbirds, and grackles. So far this year I've seen a few cowbirds, no red-wings.
This year it's a grackle posse making the rounds.
I've always loved their almost electronic squawk. And since I've been appreciating colors, here is one showing off his iridescence.