Apologies. This is a very old string but I found it trying to find the answer to an experience I had way back in 1963, 4 or 5.
I was an Air cadet as a 16 yr old or so and my mates and I had been on camp at RAF Linton on Ouse, UK. We had been out on the town and were returning to barracks walking across the air field after dark. To our fascination we saw what to us was a UFO. It was a strange light point source flying above us at an indeterminate altitude. It was about the same size as a star, but was yellow not star white. We took it to be high up because the light source was quite small and we could hear no noise from it. Its angular speed was quite high, moving over us from one horizon to the other in only 30 seconds or so.
It could have been a high altitude aircraft or perhaps a satellite but one thing in particular mediated against it being either. Every 3 or 4 seconds it made quick wiggling movements from site to side. If it was an aircraft or a satellite, these wiggling movements would result in horrendous acceleration forces on whatever it was.
So pin point yellow light, speeding across the sky and wiggling from side to side in a manner than said it could not be an aeroplane or satellite. We had no idea. It was a really fascinating big mystery!
Then the most serendipitous moment of my life. As a group of mates we went to the cinema a few weeks after we came home from camp. In those days Pathe news would present a short set of documentaries on some interesting news. You can look at some of these at https://www.britishpathe.com/
And to our amazement we viewed what was most likely the answer to our puzzle.
The film showed the work of a biologist in Yorkshire who was researching into how geese navigated. To look at any possible use of the Sun, he wanted to watch them take off in the dark. To be able to see them he had attached a small battery driven light bulbs to their legs. This explained the yellow nature of the light, its angular speed over us and the fact that it wiggled from side to side every few seconds -- when the bird flapped its wings!
I have searched for this film for some time now and would be really grateful if anybody here could help me. Cheers.