Commercial Varieties of Sunflower Seeds

• Sunflower seeds are a healthy snack -- high in protein, vitamin E, antioxidants and fat. They also make excellent birdseed for a wide range of species like cardinals and sparrows. Commercial sunflower seeds come in several varieties that are widely available in food stores and garden supply stores. Sunflower seed varieties share a lot in common but do differ in a number of important ways.

Black Oil Sunflower Seed

• According to the Virginia Cooperative Extension, the black oil variety is the most "attractive sunflower seed" for wild birds. A wide range of small, seed-eating birds will eat black oil sunflower seeds, including chickadees, cardinals, woodpeckers, nuthatches, mourning doves, sparrows, blue jays and finches. The high concentration of oil in these seeds is beneficial to birds' feathers. Black oil sunflower seed is the most common variety of sunflower seed and can be purchased in any place where birdfeeding supplies are sold.

Striped Sunflower Seed

• Striped sunflower seeds are larger than the black oil type and contains a lower concentration of oil, these are also called confection seeds, according to the National Sunflower Association. Striped sunflower seeds have harder shells, so certain bird species won't eat them. The advantage of striped sunflower seeds is that they tend to last longer than black oil seeds, though most birds won't eat old, soggy seeds. In general, however, striped sunflower seeds are preferred for human consumption -- the largest ones are sold for in-shell human consumption, medium for hulling and the smallest for the bird and pet market, according to the National Sunflower Association.

Hulled Sunflower Seed

• Often sold as salted sunflower hearts and chips as a snack food, hulled sunflower seeds are striped sunflower seeds sold with their shells already removed. Just about any seed-eating bird will eat hulled sunflower seeds -- provided they are not salted or roasted -- and they offer most of the same nutritional benefits as the shelled varieties. This seed is particularly suited to small birds that have trouble opening shells, such as the American goldfinch. Note that when used as birdseed, this seed has a greater tendency to rot in wet weather.