I shot a drake canvasback that was 13+ years old. The band was thread bare and had to be etched to get the data. I believe I shot the bird in 1994 or 95 and didn't find out about the etching process until 98 or 99. At that point I was still worried about getting the band returned to me, but there was no problem, got the band and the certificate. He was banded on the Chesapeake and I shot him near Willmar, MN.
My dad got one at the same place in 1981 that was also banded on the Chesapeake. That bird was at least 4 years old and currently hangs on my wall.
Bands are few and far between with me and the folks I hunt with, so they are an awesome trophy that answers a few of the duck hunters' age old question . . . when, where, how old, etc.
NR