Red-winged Blackbirds, Cowbirds, and Grackles will flock to feeders especially in the early spring months when they are migrating back into Upstate New York. These birds will often feed from the ground or on feeders with large perches. Blackbirds are not finicky eaters and will readily eat black oil sunflower, sunflower hearts, cracked corn, millet, and peanut hearts.