The adult grackle has a long dark bill, pale yellowish eyes and a long tail. The plumage is an iridescent black, or purple on the head. The adult female is a bit smaller and less glossy. Grackles' nests are well-concealed cups in dense trees or shrubs, usually near water. Sometimes, they will nest in cavities or in man-made structures like eaves. They often nests in colonies, some being as high as 200 pairs.
Predators of the grackle include hawks, owls, and harriers. In addition, cats, squirrels, snakes, and raccoons sometimes eat grackle eggs.