Autumn Sights

It's Autumn and migration season for the birds flying south. All night long with regular frequency, we could see birds crossing the face of the Moon when looking in the telescope. Most would flutter across, wings beating, tiny compared to the disk of the Moon in the field of view. It appeared to be random trajectories, but watching them fly by most ingressed from the terminator side, corresponding roughly to a north - south direction. I asked some of the folks about how birds might use the Moon for migration and navigation but no one really knew.