Banded birds - ducks, geese etc. are birds that have a metal or plastic band around thier ankle or neck (geese). These bands are placed for various reasons. Including, but not limited to determining migration routes, age, and overall well being of the individual bird and habitat.
Banding can and has been done on indvidual, organizational, and governmental levels.
Bands tend to be quite rare in the grand scheme of things...so to get a bird that is banded is too. Most people keep the bands to themselves and torphies or keepsakes. Some go the distnace to report the band and thereby help to complete the research on that individual bird.
For one of the more renowned persons in banding check this out: http://www.jackminer.com/