bird ringing

A researcher uses ringing pliers to attach a ring to the leg of a Eurasian blackcap. Ringing a black-headed gull Chroicocephalus ridibundus (Laridae) nestling A box of equipment for measuring, weighing and ringing birds. Ringed sandhill crane (Grus canadensis) at the Llano Seco Unit of the Sacramento National Wildlife Refuge Complex

Bird ringing (UK) or bird banding (US) is the attachment of a small, individually numbered metal or plastic tag to the leg or wing of a wild bird to enable individual identification. This helps in keeping track of the movements of the bird and its life history. It is common to take measurements and examine the conditions of feather moult, subcutaneous fat, age indications and sex during capture for ringing. The subsequent recapture, recovery, or observation of the bird can provide information on migration, longevity, mortality, population, territoriality, feeding behaviour, and other aspects that are studied by ornithologists. Other methods of marking birds may also be used to allow for field based identification that does not require capture.