What animal-inspired machine did Leonardo da Vinci design to imitate a bird’s flight?

Leonardo da Vinci designed an ornithopter to imitate a bird’s flight.

An ornithopter is a flying machine that produces lift through flapping wings. Leonardo studied birds, bats, wing structure, and air resistance while developing several designs for human flight. His sketches show mechanisms intended to transmit movement from a pilot to wings, generally through pedals, levers, or other mechanical linkages.

Leonardo understood that human muscles alone would not easily provide the power required for a large flapping machine. His ornithopter projects therefore remained experimental concepts rather than successful aircraft. They are important because they show a systematic attempt to connect anatomy, observation, and mechanical design.

An ornithopter is different from a glider, which has fixed wings, and from a helicopter, which uses rotating blades. Modern ornithopters have been built as small experimental aircraft and robotic devices, but Leonardo’s proposed full-sized machines were never documented as completing powered flight.