I have seen many eagles and hawks out west make maneuvers without using their wings. It is amazing what they can do, and I hope an avian expert will check out this video.
Where someone sees an extraterrestrial craft, I see the legs and a possible outline of a bird's head.
People want to see flying saucers in everything that is out there. 90% of what is seen has a down to Earth explanation. The eagle/hawk explanation works for me as I have watched these amazing birds in motion.