1. Beak: The shape and size of a bird's beak are adapted for specific diets. For example, hummingbirds have long, thin beaks for sipping nectar from flowers, while eagles have hooked beaks for tearing meat.
2. Feathers: Feathers are lightweight, insulating, and aerodynamic. They help birds fly efficiently and stay warm in cold weather.
3. Wings: Birds have powerful wings that allow them to fly. The shape and size of a bird's wings are also adapted for specific types of flight. For example, soaring birds have long, broad wings, while flapping birds have shorter, narrower wings.
4. Tail feathers: Birds use their tail feathers for steering and balance. They also help birds to avoid predators by changing direction quickly.
5. Feet: Birds have feet that are adapted for perching, walking, swimming, or catching prey.
6. Eyes: Birds have excellent eyesight, which helps them to find food and avoid predators. Some birds, such as owls, have eyes that are adapted for seeing in low light.
7. Ears: Birds have good hearing, which helps them to communicate with each other and to avoid predators. Some birds, such as owls, have ears that are adapted for hearing high-frequency sounds.
8. Air sacs: Birds have a system of air sacs that helps them to breathe efficiently. Air sacs also help to reduce the weight of a bird's body.
9. Crop: Birds have a crop, which is a storage pouch in the esophagus. The crop helps birds to store food and to digest it slowly.
10. Gizzard: Birds have a gizzard, which is a muscular stomach. The gizzard helps birds to grind up food and to break down hard materials.