The ability to fly in animals is one of the masterpieces of evolution. The ecological advantages include a rapid escape mechanism, and rapid and relatively (energetically) cheap transport. Even though humans have been interested in bird flight for centuries, the interest remains at a high level and modern research is steadily revealing new findings. The flying animal is the ideal model system for the organismal biologist, because it offers challenges in aerodynamics, material science, physiology, neurobiology and ecology, and their interactions.