Its luck and location like TFA said. Mostly though it is luck.

Quite often, biologists will band birds in the same spots year after year. Birds of course, are prone to following the same migration paths year after year. Hence the consistancy. There are some Septembers, where is the banders come by the park, every single goose we shoot will be banded... often between the lot of us, we can string five or six consecutive numbers together. That sort of makes it not as special, trust me.

And lots of folks too get bands made, and by them on ebay.... so don't think every full lanyard you see is the real deal. Often, unless its a call maker or some sort of pro hunter who gets paid to show off... its a bunch of phoneys. Why hunters bring bands to the field, bands that shine, clank, and are personally valuable, is beyond me. Mine stay at home on a lanyard with a few old, sentamental calls. My certs are laminated and bound in a photo album... I can replace $400 worth of duck calls... but never my little trophies of good hunts gone by.