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

in Amphibia-Reptilia
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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 (I3S) 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.

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

in Amphibia-Reptilia


AngeliniC.AntonelliD.UtzeriC. (2010): Capture-mark-recapture analysis reveals survival correlates in Salamandrina perspicillata (Savi, 1821). Amphibia-Reptilia 31: 21-26.

AtzoriA.BertiF.CencettiT.FornasieroS.TamburiniM.ZuffiM.A.L. (2007): Advances in methodologies of sexing and marking less dimorphic gekkonid lizards: the study case of the Moorish gecko, Tarentola mauritanica. Amphibia-Reptilia 28: 449-454.

BarbadilloL.J.LacombaJ.I.Pérez MelladoV.SanchoV.López-JuradoL.F. (1999): Anfibios y Reptiles de la Península Ibérica Baleares y Canarias. Editorial Planeta Barcelona.

BendikN.F.MorrisonT.A.GluesenkampA.G.SandersM.S.O’DonnellL.J. (2013): Computer-assisted photo identification outperforms visible implant elastomers in an endangered salamander, Eurycea tonkawae. PLOS ONE 8: e59424.

BlochN.IrschickD.J. (2004): Toe-clipping dramatically reduces clinging performance in a pad-bearing lizard (Anolis carolinensis). J. Herpetol. 37: 293-298.

BolgerD.T.MorrisonT.A.VanceB.LeeD.FaridH. (2012): A computer-assisted system for photographic mark-recapture analysis. Meth. Ecol. Evol. 3: 813-822.

DaugmanJ.DowningC. (2001): Epigenetic randomness, complexity and singularity of human iris patterns. Proc. R. Soc. Lond. B 268: 1737-1740.

DaugmanJ.DowningC. (2013): No change over time is shown in Rankin et al. “Iris recognition failure over time: the effects of texture”. Pattern Recogn. 46: 609-610.

DaviesT.K.StevensG.MeekanM.G.StruveJ.RowcliffeJ.M. (2013): Can citizen science monitor whale-shark aggregations? Investigating bias in mark-recapture modelling using identification photographs sourced from the public. Wildlife Res. 39: 696-704.

FrischA.J.HobbsJ.P.A. (2007): Photographic identification based on unique, polymorphic colour patterns: A novel method for tracking a marine crustacean. J. Exp. Mar. Biol. Ecol. 351: 249-299.

GambleL.RavelaS.McGarigalK. (2008): Multi-scale features for identifying individuals in large biological databases: an application of pattern recognition technology to the marbled salamander Ambystoma opacum. J. Applied Ecol. 45: 170-180.

HareK.M.CreeA. (2005): Natural history of Hoplodactylus stephensi (Reptilia: Gekkonidae) on Stephens Island, Cook Strait, New Zealand. New Zeal. Ecol. 29: 137-142.

HastingsK.K.HibyL.A.SmallR.J. (2008): Evaluation of a computer-assisted photographic-matching system to monitor naturally marked harbor seals at Tugidak island, Alaska. J. Mammal. 85: 1201-1211.

KarlssonO.HibyL.LundbergT.JüssiM.JüssiI.HelanderB. (2005): Photo-identification, side fidelity, and movement of female gray seals (Halichoerus grypus) between haul-outs in the Baltic Sea. Ambio 34: 628-634.

KellyM.J. (2001): Computer-aided photograph matching in studies using individual identification: an example from Serengeti cheetahs. J. Mammal. 82: 440-449.

R Development Core Team (2007): R: A Language and Environment for Statistical Computing. R Foundation for Statistical ComputingVienna, Austria. Available at

RebeloR. (2008): Tarentola bischoffi. In: Atlas dos Anfíbios e Répteis de Portugal p.  188-189. LoureiroA.Ferrand de AlmeidaN.CarreteroM.A.PauloO.S. Eds Instituto de Conservação da Natureza e da BiodiversidadeLisboa.

ReisserJ.ProiettiM.KinasP.SazimaI. (2008): Photographic identification of sea turtles: method description and validation, with an estimation of tag loss. Endang. Species Res. 5: 73-82.

RibeiroJ.RebeloR. (2011): Survival of Alytes cisternasii tadpoles in stream pools: a capture-recapture study using photo-identification. Amphibia-Reptilia 32: 365-374.

SacchiR.ScaliS.Pellitteri-RosaD.PupinF.GentilliA.TettamantiS.CavigioliL.RacinaL.MaiocchiV.GaleottiP.FasolaM. (2010): Photographic identification in reptiles: a matter of scales. Amphibia-Reptilia 31: 489-502.

SalvidioS.OnetoF. (2008): Density regulation in the Mediterranean leaf-toed gecko Euleptes europaea. Ecol. Res. 23: 1051-1055.

SchofieldG.KatselidisK.A.DimopoulosP.PantisJ.D. (2008): Investigating the viability of photo-identification as an objective tool to study endangered sea turtle populations. J. Exp. Mar. Biol. Ecol. 360: 103-108.

SpeedC.W.MeekanM.G.BradshawC.J.A. (2007): Spot the match – wildlife photo-identification using information theory. Front. Zool. 4: 1-11.

Van DammaR.VervustB. (2009): Marking lizards by heat branding. Herp. Rev. 40: 173-174.

Van TienhovenA.M.Den HartogJ.E.ReijnsR.A.PeddemorsV.M. (2007): A computer-aided program for pattern-matching of natural marks on the spotted raggedtooth shark Carcharias taurus. J. Applied Ecol. 44: 273-280.

VasconcelosR.PereraA.GeniezP.HarrisD.J.CarranzaS. (2012): An integrative taxonomic revision of the Tarentola geckos (Squamata, Phyllodactylidae) of the Cape Verde Islands. Zool. J. Linnean Soc. 164: 328-360.

WangerT.C.MotzkeI.FurrerS.C.BrookB.W.GruberB. (2009): How to monitor elusive lizards: comparison of capture-recapture methods on giant day geckos (Gekkonidae, Phelsuma madagascariensis grandis) in the Masoala rainforest exhibit, Zurich Zoo. Ecol. Res. 24: 345-353.


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    Tarentola boettgeri bischoffi head profile illustrating the unique variegated iris pattern. The vertical arrows correspond to the three reference points used in the I3S fingerprint and the horizontal arrows relate to the three types of iris features used for identification purposes: line interceptions, conspicuous vertices and dots.

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    Head profiles of two Tarentola boettgeri bischoffi photographed between June 2009 and May 2011. Images (a) and (b) correspond respectively to the right and left profiles of an individual captured in June 2009, and images (c) and (d) to the same individual recaptured in April 2010. Images (e) and (f) correspond to the right profiles of a gecko captured in June 2009 and recaptured in May 2011.

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