Why is the beak of a bird streamline?

Birds' beaks are not streamlined. They are adapted to the specific feeding habits and lifestyles of different bird species. For example, the beaks of hummingbirds are long and thin, allowing them to reach deep into flowers to access nectar. The beaks of eagles and hawks are hooked and sharp, helping them tear through flesh and bone. The beaks of some shorebirds are long and spoon-shaped, allowing them to probe through mud and water for small invertebrates.