Banding returns tend to be poor--001% for small birds. Some duck hunters don't even report bands, since they are afraid of government interference in their sport. The Fish and Wildlife Service has had to resort to award bands, worth varying amounts of cash. Hunters are the weak link in wildlife management.
In moon watching, you train telescopes on the moon. By counting bird shadows, you can estimate numbers in the air and direction of their migration. George Lowery conducted a nationwide survery of migration during four nights in October.
The images of birds by radar is often spectacular and warns of danger to planes.
Banding Cliff Swallows