Birds eat a diversity of food including small mammals, reptiles, other birds, fish, insects, plants, nectar, pollen and seeds. These foods present a spectrum of nutrient compositions that can not be represented in a single substitute food.
Birds can be broadly divided into the following three groups based upon their major dietary requirements:
Seed & Fruit Eaters (Granivores)
Insect & Meat Eaters (Insectivores)
Nectar & Pollen Eaters (Nectarivores)