Iris photo-identification: A new methodology for the individual recognition of Tarentola geckos

Gekkonid field studies are hampered by the difficulty to individually recognize individuals. In this study we assess the feasibility of using their variegated iris pattern to photo-identify Tarentola boettgeri bischoffi, a threatened Macaronesian endemic. Using a library of 924 photos taken over a 9-month period we also evaluate the use of the pattern matching software Interactive Individual Identification System ( (IS)-S-3) to match photos of known specimens. Individuals were clearly recognized by their iris pattern with no misidentifications, and using I3S lead to a correct identification of 95% of the recaptures in a shorter time than the same process when conducted visually by an observer. The method's feasibility was improved by increasing the number of images of each animal in the library and hindered by photos that deviate from a horizontal angle.