Bird food
Bird food or bird seed is food (often varieties of seeds, nuts, and/or dried fruits) consumed by wild and domestic birds. While most bird food is fed to commercial fowl (chicken, turkey), people also use bird food to feed their pet birds or provide a feeding site for wild birds. The various types of bird food reflect the species of bird that can be fed, for example, whether they are carnivores, herbivores, insectivores, nectar-eating birds, etc. Bird food can also differ by the feeding strategies employed by beaks in cracking the seed coat and obtaining the seeds  inside (hooked versus straight beaks, for example). Sunflower seeds attract the widest variety of birds, and so often form the mainstay backyard bird feeders. However, other varieties of seed can help attract different types of birds to gardens and backyards. In general, mixtures that contain red millet, oats, and other "fillers" are not attractive to most birds and can lead to a lot of waste as the birds sort through the mix, as well as the potential for fungal and bacterial growth. While it is a popular practice to feed wild birds from bird feeders, they can carry potential risks  for the birds that feed there, such as disease, malnutrition, and predation by domestic animals. Researchers recommend that bird feeders be disinfected every time they are refilled. Types. Natural. Seed. Black sunflower seeds are highly recommended for use in bird feeders because they attract a wide variety of birds, have a high ratio of seed material to shell, and are high in fat content (especially important for winter birds). Other common bird seeds include Niger, or thistle seed, a favorite of goldfinches, redpolls. Millet for sparrows and juncos as well as safflower for cardinals, among others. Non-seed. Suet is  recommended for insect-eating birds like nuthatches and woodpeckers. Artificial nectar – essentially sugar water – attracts hummingbirds. Bread and kitchen scraps are often fed to ducks and gulls (although this can lead to nutrient deficiencies and increased defecation for the birds in question). Chickens are commonly fed maize, wheat, barley, sorghum and milling by-products, in a mixture traditionally called chicken scratch. Pet parrots are fed fresh fruit, vegetables and nuts (in addition to seed). These seeds and non-seed supplies are commonly obtained as by-products on farms, but can also be bought from independent retailers. Commercial. Non Farm. Commercial  bird food is widely available for feeding wild and domesticated birds, both seed combinations and pellets. When feeding wild birds the Royal Society for the Protection of Birds (RSPB) suggests that it be done year-round, with different mixes of nutrients being offered each season. Selections should have additional fat content in the winter months, and additional proteins in the form of nuts, seeds, and dried worms in summer when birds are changing their plumage and maybe molting. Farm. Farmed birds fed commercial bird food typically are given very specific, scientifically designed, pre-blended feed. Examples of commercial bird food  for chickens include chick starter medicated crumbles, chick grower crumbles, egg layer mash, egg layer pellet, egg layer crumbles, egg producer pellet, and boilermaker med crumbles. Pellet crumbles are often prepared for tiny chicks. Mash is more finely ground.