Avian anatomy refers to the physical structure of birds, which is uniquely adapted for flight. Birds have lightweight skeletons with hollow bones that reduce body weight without sacrificing strength. Their wings are modified forelimbs, featuring feathers that provide lift and enable flight. The beak, or bill, varies in shape and size depending on the bird's diet and feeding habits. In addition to their skeletal adaptations, birds possess a specialized respiratory system that includes air sacs, allowing for efficient oxygen exchange during flight. Their digestive system is also unique, featuring a gizzard that grinds food, aiding in digestion. Overall, avian anatomy is a remarkable example of evolution tailored for aerial life.