Analyzing Rebanded Birds
From the beginning of the banding program to the end of the calendar year 1967, when a bird was rebanded, the original band number was used on all banding records. In 1968, provision was made for printing TWO band numbers on the Report-to-Bander: the original number, and the number actually reported by the finder. However, the band number entered in the statistical record in the recovery file is the number reported by the finder.
Banders requesting data from the Bird Banding Laboratory files are warned that species that outlive their bands can have more than one band number. There may be more than one encounter of the same bird under different band numbers. For recaptured birds, records should be individually checked and corrected in order to accurately estimate return and recovery rates, age ratios and mortality and survival rates.
The data for the original banding (age-sex, status, location, date), and the permit number of the original bander are available from the Recovery Statistical Record.
Birds rebanded by you can be identified from your own records. For birds rebanded by others, you may request the original band numbers from the Bird Banding Laboratory. Avoid having more than one bander working on the same local population of birds or have several banders under a master permit cooperate in studies.
The original bander will receive a "Report to Bander" listing for each instance of band replacement and subsequent encounter. The person replacing the band will receive a Certificate of Appreciation (Figure 4.8) which includes the name and address of the original bander for that one encounter. Subsequent encounters will result in a "Report to Bander" for all banders involved.