Biomechanics of avian flight

Throughout recorded human history, birds have fascinated and inspired humans to dream of flying. The Greek myth of Daedalus and his son Icarus, who flew too close to the sun and fell to his death, first written by Diodorus (60–30 B.C.E.) and later poetically revised by Ovid (8 C.E.), evokes the dangers of hubris. Many indigenous peoples invoke spiritual qualities and protection ascribed to birds that were symbols of freedom and viewed as sacred messengers of the gods. As a student of bird flight, Leonardo da Vinci (1452–1519) was the first to document dynamic soaring by birds. And, subsequently, the flight of birds inspired human engineered pursuit of powered aircraft design, with the Wright Brothers being the first to design and achieve sustained flight at Kitty Hawk, NC, USA in 1903. In this Primer, Biewener examines the evolution of the key features that make possible avian flight, such as flight feathers and skeletal modifications of the wings and thorax, and considers how flight muscles function to achieve the high power output required for successful flight.