Individual peregrine falcons (Falco peregrinus) may be identified by comparing their toe-scale patterns. Comparisons are, however, very tedious when dealing with a large number of birds. This study developed a computer-assisted classification system to facilitate the identification process, based on visual analysis of photographs of the dorsal surface of the middle toes of both feet.
One-hundred-eighty photographs of right and left feet of 90 peregrine falcons (F.p. anatum) were analyzed. Toe-scale patterns were classified on the basis of similarities, reducing the number of prints for visual comparison to a more practical level.
The classification system was based on the formulation of an alphanumeric code which distinguished right from left feet, and single from double scales. Each code was entered into a computerized filing program.
To determine whether a “suspect” print was included in the computer file, it was characterized in a similar manner. The code was entered into the search option of the filing program, which displaced all similar code sequences in the file. The “suspect” print could then be compared visually with each of the possible matches until a correct match was found.
Using prints from both feet, conscientious evaluators with minimal training and no prior experience in using the system were able to correctly identify “suspect” falcons with a high rate of success.