Translations:Adventist Youth Honors Answer Book/Nature/Birds - Advanced/27/en

A ring of suitable size is attached, and has on it a unique number, plus a contact address. The bird is often weighed and measured, and examined for parasites (which may then be removed) before release. The rings are very light-weight, and have no adverse effect on the birds. The individual birds can then be identified when they are re-trapped, or found dead.