Seeds offer a high oil content to keep busy birds energized. Probably the most readily available commercial bird food, seed mixes are also popular with the vast majority of garden birds. In particular, sunflower seeds are universally favored. Choose black sunflower over striped, as the oil content is considerably higher. Pre-shelled sunflower seeds are popular with gardeners because they minimise the mess left. Black nyjer seed will attract siskins and goldfinches, but their diminutive size requires a specialised feeder.