Black oil sunflower seed is the most familiar and most popular type of birdseed, for good reason. With this one type of seed in your feeders, you will attract dozens of bird species to your backyard. About Black Oil Sunflower Seed All types of sunflower seeds originate from the common sunflower, Helianthus annuus. There are many specialized and hybrid flower varieties that create different bloom sizes, stalk heights and seed yields. The seeds they produce are similar, however, and sunflower seed is a universally popular birdseed. When compared to striped sunflower seeds, black oil seeds are meatier and have a higher oil content, giving birds more nutrition and calories in every bite. Black oil seeds also have thinner shells, making them easier for small birds to crack. The general nutritional components of black oil sunflower seed are: 28 percent fat 25 percent fiber 15 percent protein Calcium B vitamins Iron Vitamin E Potassium This makes black oil sunflower seed a valuable and nutritious part of any backyard bird’s diet.