Storks often use soaring, gliding flight, which conserves energy. Soaring involves thermal air currents. Ottomar Anschütz's well-known 1884 album of photos of storks motivated the look of Otto Lilienthal's experimental gliders in the late nineteenth century. In 1942 Heinrich Himmler sought to make use of storks to hold Nazi propaganda https://arthurfe83e.tinyblogging.com/a-secret-weapon-for-stork-70255324