If you had to choose only one seed, we would recommend black-oil sunflowers. These seeds are liked by the widest variety of birds, are economical, and have high protein and fat content. Attracts Cardinals, Chickadees, Purple Finches, Gold Finches, Tufted Titmice, Nuthatches, Woodpeckers, Sparrows, Doves, Grosbeaks, Pine Siskens. However, Striped sunflower seeds have a thicker shell, much harder for House Sparrows and blackbirds to crack open. So if you’re inundated with species you’d rather not subsidize at your black oil sunflower, before you do anything else, try switching to striped sunflower.