I watched this common grackle going through some complicated maneuvering this morning, in order to, what it looked like to me, get a drink of water. It wasn't until I enlarged my shot that I realized it was after a winged insect of some kind.
Grackles, of course, are not exclusive to fresh-water marsh habitats; as a matter of fact a couple have become a nuisance at my sunflower feeder. But they seem to like to nest near water, and they are nearly as prevalent as the Red-winged Blackbirds at the marsh. I think this female Common Grackle has a nest close to the marsh edge, as I have seen her a number of times perched on these Curly Dock stems, twice with a worm in her beak.