THE RINGING ACTIVITY
The study about the birds' migration made big progresses thanks to the ringing practice. The data issued by this activity, in fact, are useful both for research and management purposes. The monitoring of single birds supports the studies on dispersion and migration, behavior and social structure, longevity and surviving rates, reproductive success and demographic growth.
The ringing activity consists of putting on the leg of each caught bird an aluminium ring, on which the identification number and the address of the central reference institute of the issuing country have been engraved. This implies that if a dead ringed bird is found, the ring should be sent to the written address, specifying the date and place of retrieving. The anlysis of the recapture/retrieving of rings supplies for important information about itineraries, areas of overwintering, migration speed and maximum age reached by free birds.
Nowadays there are ten different sizes of rings, according to the dimensions of the species.
Birds are caught thanks to a system of standardized mist-nets. The nets are operative from the dawn until the sunset and they are checked evary hour, according to the weather conditions. Each cought bird receive a ring and parameters like age, sex, biometric mesures and physiologic conditions. The lenght of the wing is measured on the third primary remigant, while the weight is recorded thanks to electronic scale (grams). For the species belonging to Passerines, the fat accumulation is measured according to the Busse scale (range 0 to 5). All the data are registered in a database implemented by ISPRA.