Close ringing
Placing a ring on a bird's leg at the stage when its foot is still small enough for the ring to be slipped over it, so that a 'closed' ring can be used instead of one in the form of a strip which has to be closed with a pair of ringing pliers. Close ringing is the method used in aviculture, and a bird ringed in this way can be regarded as having a captive origin.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver