Cuttlebone is essential for birds of all sizes. It helps keeps beaks trimmed and provides calcium, iron, and other trace minerals. Helps keeps the beak trimmed. Provides Calcium, Iron, and Other Trace Minerals. For Birds Of All Sizes. Cuttlebone is essential for all birds and promotes good health by keeping beaks and nails trimmed. Since cuttlebone is a natural product, it may vary slightly in both color and size.