Bird ringing or bird banding 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 conditions of feather molt, subcutaneous fat, age indications and sex during capture for ringing. The subsequent recapture or recovery of the bird can provide information on migration, longevity, mortality, population, territoriality, feeding behaviours, 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. The earliest recorded attempts to mark birds were made by Roman soldiers. One instance occurred during the Punic Wars: In 218 BC a crow was released by a besieged garrison (which suggests that this was an established practice). Quintus Fabius Pictor used a thread on the bird's leg to send a message back. In another instance, a knight interested in chariot races during the time of Pliny (AD 1) took crows to Volterra, 135 miles (217 km) away and released them with information on the race winners.