{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T01:43:49Z","timestamp":1792028629499,"version":"4.4.0"},"reference-count":50,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T00:00:00Z","timestamp":1770681600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002428","name":"Austrian Science Fund","doi-asserted-by":"publisher","award":["ESP 239-B"],"award-info":[{"award-number":["ESP 239-B"]}],"id":[{"id":"10.13039\/501100002428","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011019","name":"Nemzeti Kutat\u00e1si Fejleszt\u00e9si \u00e9s Innov\u00e1ci\u00f3s Hivatal","doi-asserted-by":"publisher","award":["grant K-135016"],"award-info":[{"award-number":["grant K-135016"]}],"id":[{"id":"10.13039\/501100011019","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry for Culture and Innovation Hungary","award":["\u00daNKP-23-4"],"award-info":[{"award-number":["\u00daNKP-23-4"]}]},{"name":"Ministry for Culture and Innovation Hungary","award":["EK\u00d6P-MATE\/2024\/25\/K"],"award-info":[{"award-number":["EK\u00d6P-MATE\/2024\/25\/K"]}]},{"name":"Ministry for Culture and Innovation Hungary","award":["EK\u00d6P-24-4-II-ELTE-364"],"award-info":[{"award-number":["EK\u00d6P-24-4-II-ELTE-364"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    In amphibian capture-recapture studies, commonly used individual-identification methods include toe clipping as well as less invasive alternatives of varying cost. Yet, choosing the best method for a study is challenging, because both the reliability for identification and the severity of adverse effects of a given mark type can greatly vary between species as well as life stages. We compared the reliability of three identification methods in young agile frogs (\n                    <jats:italic>Rana dalmatina<\/jats:italic>\n                    ): clipping a single phalanx, injecting visible-implant-elastomer (VIE) tags (one of six colours) under the skin, and photo-based identification using natural colouration. Individuals were regularly photographed from the start of metamorphosis onwards, and were marked by the other two methods soon after all of them finished metamorphosis. Subsequently, we checked mark retention by each method multiple times for more than a year. Photo-based identification was far more reliable than the other two methods: 100% identification success post-metamorphosis in all checking events within small housing groups, and 98% with computer-assisted identification across all housing groups. Post-metamorphic body colouration remained largely stable, and the major patterns were already present at metamorphosis. Based on VIE colour alone, we could correctly identify the animals in 77% of the checks. Green tags were the easiest to recognize. VIE often broke into smaller parts, and those were sometimes found only outside the originally tagged body part (15%) or not found at all (10%). VIE was better retained in the legs than in the arms. Dissection revealed that migrating VIE pieces can accumulate in the internal organs, especially the kidneys. The clipped toe tip was successfully recognized only in 41% of checks. We conclude that photo-based identification is superior to both VIE-tagging and toe tipping in young agile frogs, and this method should be preferred in future studies seeking a cost-efficient yet reliable identification method in this species.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0342340","type":"journal-article","created":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T18:29:40Z","timestamp":1770748180000},"page":"e0342340","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Photo-based individual identification is more reliable than visible implant elastomer tags or toe-tipping in young agile frogs"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0179-1153","authenticated-orcid":true,"given":"Edina","family":"Nemesh\u00e1zi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9610-0353","authenticated-orcid":true,"given":"Nikolett","family":"Ujhegyi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4853-9331","authenticated-orcid":true,"given":"Zsanett","family":"Mik\u00f3","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2075-0776","authenticated-orcid":true,"given":"Andrea","family":"K\u00e1sler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vera","family":"Lente","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2136-5346","authenticated-orcid":true,"given":"Veronika","family":"B\u00f3kony","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,2,10]]},"reference":[{"key":"pone.0342340.ref001","unstructured":"Murray DL, Fuller MR. A critical review of the effects of marking on the biology of vertebrates. In: Boitani L, Fuller TK, editors. Research Techniques in Animal Ecology: Controversies and Consequences. New York: Columbia University Press; 2000. pp. 15\u201364."},{"key":"pone.0342340.ref002","author":"WMS Russell","year":"1992"},{"key":"pone.0342340.ref003","doi-asserted-by":"crossref","DOI":"10.1016\/j.gecco.2025.e03582","article-title":"The impact of toe-clipping on animal welfare in amphibians: A systematic review","volume":"59","author":"MA Zemanova","year":"2025","journal-title":"Global Ecology and Conservation"},{"issue":"3","key":"pone.0342340.ref004","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1163\/157075408785911002","article-title":"Technology meets tradition: A combined VIE-C technique for individually marking anurans","volume":"5","author":"K Hoffmann","year":"2008","journal-title":"Appl Herpetol"},{"issue":"3","key":"pone.0342340.ref005","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1163\/157075409X420042","article-title":"Evaluation of a new technique for marking anurans","volume":"6","author":"A Harding","year":"2009","journal-title":"Appl Herpetol"},{"key":"pone.0342340.ref006","doi-asserted-by":"crossref","first-page":"217","DOI":"10.2307\/1566111","article-title":"Individual recognition of amphibians: effects of toe clipping and fluorescent tagging on the salamander Plethodon vehiculum","volume":"35","author":"TM Davis","year":"2001","journal-title":"J Herp"},{"key":"pone.0342340.ref007","first-page":"305","article-title":"Toe-clipping as an acceptable method of identifying individual anurans in mark recapture studies","volume":"38","author":"AD Phillott","year":"2007","journal-title":"Herpetol Rev"},{"key":"pone.0342340.ref008","first-page":"403","article-title":"Evaluation of the photographic identification method (PIM) as a tool to identify adult Litoria genimaculata (Anura: Hylidae)","volume":"4","author":"N Kenyon","year":"2009","journal-title":"Herpetol Conserv Biol"},{"issue":"4","key":"pone.0342340.ref009","doi-asserted-by":"crossref","first-page":"670","DOI":"10.1643\/CH-12-129","article-title":"Factors Influencing Survival and Mark Retention in Postmetamorphic Boreal Chorus Frogs","volume":"2013","author":"JE Swanson","year":"2013","journal-title":"Copeia"},{"issue":"1","key":"pone.0342340.ref010","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1655\/HERPETOLOGICA-D-13-0004","article-title":"Visible Implant Elastomer Marking Does Not Affect Short-term Movements or Survival Rates of the Treefrog Litoria rheocola","volume":"70","author":"SJ Sapsford","year":"2014","journal-title":"Herpetologica"},{"key":"pone.0342340.ref011","doi-asserted-by":"crossref","DOI":"10.7717\/peerj.9630","article-title":"Visible implant elastomer (VIE) success in early larval stages of a tropical amphibian species","volume":"8","author":"CA Fouilloux","year":"2020","journal-title":"PeerJ"},{"issue":"2","key":"pone.0342340.ref012","doi-asserted-by":"crossref","DOI":"10.1670\/22-011","article-title":"Long-term Retention, Readability, and Health Effects of Visible Implant Elastomer (VIE) and Visible Implant Alpha (VI Alpha) Tags in Larval Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)","volume":"57","author":"DD Knapp","year":"2023","journal-title":"Journal of Herpetology"},{"key":"pone.0342340.ref013","first-page":"133","article-title":"Tagging tadpoles: retention rates and impacts of visible implant elastomer (VIE) tags from the larval to adult amphibian stages","volume":"25","author":"L Bainbridge","year":"2015","journal-title":"Herpetol J"},{"issue":"3","key":"pone.0342340.ref014","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1577\/M08-138.1","article-title":"An Evaluation of Visible Implant Elastomer for Marking the Federally Listed Fountain Darter and the San Marcos Salamander","volume":"29","author":"CT Phillips","year":"2009","journal-title":"North American Journal of Fisheries Management"},{"key":"pone.0342340.ref015","doi-asserted-by":"crossref","first-page":"187","DOI":"10.32800\/abc.2020.43.0187","article-title":"Use of visible implant elastomer and its effect on the survival of an endangered minute salamander","author":"MT Oropeza\u2013S\u00e1nchez","year":"2020","journal-title":"Anim Biodiv Conserv"},{"key":"pone.0342340.ref016","first-page":"179","article-title":"Urinary corticosterone metabolite responses to capture and visual elastomer tagging in the Asian toad (Duttaphrynus melanostictus)","year":"2019","journal-title":"HJ"},{"key":"pone.0342340.ref017","first-page":"99","article-title":"Visible implant elastomer tagging and toe-clipping: Effects of marking on locomotor performance of frogs and skinks","volume":"20","author":"K Schmidt","year":"2010","journal-title":"Herpetol J"},{"key":"pone.0342340.ref018","first-page":"125","article-title":"Visual implant elastomer (VIE) tags are an unreliable method of identification in adult anurans","volume":"23","author":"LA Brannelly","year":"2013","journal-title":"Herpetol J"},{"key":"pone.0342340.ref019","first-page":"425","article-title":"Retention and readability of visible implant elastomer marks in eastern red-backed salamanders (Plethodon cinereus)","volume":"38","author":"JL Heemeyer","year":"2007","journal-title":"Herpetological Review"},{"key":"pone.0342340.ref020","first-page":"300","article-title":"Subcutaneous movements of visible implant elastomers in wood frogs (Rana sylvatica)","volume":"37","author":"DL Moosman","year":"2006","journal-title":"Herpetological Review"},{"key":"pone.0342340.ref021"},{"issue":"4","key":"pone.0342340.ref022","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1089\/zeb.2008.0551","article-title":"Pigments, patterns, and fish behavior","volume":"5","author":"AC Price","year":"2008","journal-title":"Zebrafish"},{"key":"pone.0342340.ref023"},{"key":"pone.0342340.ref024","first-page":"96","article-title":"The green toad example: A comparison of pattern recognition software","volume":"17","author":"S Burgstaller","year":"2021","journal-title":"North West J Zool"},{"issue":"15","key":"pone.0342340.ref025","doi-asserted-by":"crossref","first-page":"5861","DOI":"10.1002\/ece3.3140","article-title":"Comparison of photo-matching algorithms commonly used for photographic capture-recapture studies","volume":"7","author":"M Matth\u00e9","year":"2017","journal-title":"Ecol Evol"},{"issue":"1","key":"pone.0342340.ref026","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0341460","article-title":"Placing anurans in water can improve photo-based individual identification","volume":"21","author":"E Nemesh\u00e1zi","year":"2026","journal-title":"PLoS One"},{"key":"pone.0342340.ref027","first-page":"67","article-title":"Individual identification of the lake Oku clawed frog (Xenopus longipes) using a photographic identification technique","volume":"17","author":"U Aevarsson","year":"2022","journal-title":"Herpetol Conserv Biol"},{"key":"pone.0342340.ref028","first-page":"579","article-title":"Considerations for and use of visible implant elastomers to track and estimate abundance of juvenile boreal toads (Anaxyrus boreas boreas) in Utah, USA","volume":"53","author":"J Holcomb","year":"2022","journal-title":"Herpetological Review"},{"issue":"4","key":"pone.0342340.ref029","doi-asserted-by":"crossref","DOI":"10.1111\/eva.70093","article-title":"Higher Sex-Reversal Rate of Urban Frogs in a Common-Garden Experiment Suggests Adaptive Microevolution","volume":"18","author":"V B\u00f3kony","year":"2025","journal-title":"Evol Appl"},{"issue":"3","key":"pone.0342340.ref030","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1111\/1365-2435.12994","article-title":"Competition induces increased toxin production in toad larvae without allelopathic effects on heterospecific tadpoles","volume":"32","author":"V B\u00f3kony","year":"2017","journal-title":"Functional Ecology"},{"issue":"5","key":"pone.0342340.ref031","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1111\/acv.12851","article-title":"Chytridiomycosis and climate change: exposure to Batrachochytrium dendrobatidis and mild winter conditions do not increase mortality in juvenile agile frogs during hibernation","volume":"26","author":"A K\u00e1sler","year":"2023","journal-title":"Animal Conservation"},{"issue":"7","key":"pone.0342340.ref032","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1038\/nmeth.2019","article-title":"Fiji: an open-source platform for biological-image analysis","volume":"9","author":"J Schindelin","year":"2012","journal-title":"Nat Methods"},{"issue":"1","key":"pone.0342340.ref033","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1053\/j.jepm.2008.11.006","article-title":"Anesthetic Considerations for Amphibians","volume":"18","author":"MA Mitchell","year":"2009","journal-title":"Journal of Exotic Pet Medicine"},{"issue":"2","key":"pone.0342340.ref034","doi-asserted-by":"crossref","first-page":"11","DOI":"10.5818\/1076-3139.5.2.11","article-title":"Tricaine Anesthesia in Amphibia: A Review","volume":"5","author":"H Downes","year":"1995","journal-title":"Bulletin of the Association of Reptilian and Amphibian Veterinarians"},{"issue":"2","key":"pone.0342340.ref035","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1053\/j.saep.2005.04.003","article-title":"Amphibian Emergency Medicine and Care","volume":"14","author":"CA Hadfield","year":"2005","journal-title":"Seminars in Avian and Exotic Pet Medicine"},{"key":"pone.0342340.ref036"},{"issue":"1","key":"pone.0342340.ref037","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1670\/14-155","article-title":"Individual Identification of the Endangered Wyoming ToadAnaxyrus baxteriand Implications for Monitoring Species Recovery","volume":"50","author":"TA Morrison","year":"2016","journal-title":"Journal of Herpetology"},{"issue":"3","key":"pone.0342340.ref038","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1111\/j.2041-210X.2010.00061.x","article-title":"Using false discovery rates for multiple comparisons in ecology and evolution","volume":"2","author":"N Pike","year":"2010","journal-title":"Methods Ecol Evol"},{"key":"pone.0342340.ref039","author":"E Nemesh\u00e1zi","year":"2025"},{"key":"pone.0342340.ref040","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3897\/herpetozoa.33.e47279","article-title":"Shot the spots: A reliable field method for individual identification of Amolops formosus (Anura, Ranidae)","volume":"33","author":"NG Patel","year":"2020","journal-title":"Herpetozoa"},{"key":"pone.0342340.ref041","first-page":"126","article-title":"Temporal variation in dorsal patterns of juvenile green-eyed tree frogs, Litoria genimaculata (Anura: Hylidae)","volume":"5","author":"N Kenyon","year":"2010","journal-title":"Herpetol Conserv Biol"},{"issue":"1","key":"pone.0342340.ref042","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1163\/15685381-bja10025","article-title":"Performance of visual vs. software-assisted photo-identification in mark-recapture studies: a case study examining different life stages of the Pacific Horned Frog (Ceratophrys stolzmanni)","volume":"42","author":"C Bardier","year":"2020","journal-title":"Amphib-Reptilia"},{"key":"pone.0342340.ref043","first-page":"204","article-title":"Effectiveness and reliability of photographic identification methods for identifying individuals of a cryptically patterned toad","volume":"15","author":"HP Davis","year":"2020","journal-title":"Herpetological Conservation and Biology"},{"key":"pone.0342340.ref044","first-page":"428","article-title":"Comparison of three widely used marking techniques for adult anuran species Litoria verreauxii alpina","volume":"9","author":"LA Brannelly","year":"2014","journal-title":"Herpetological Conservation and Biology"},{"key":"pone.0342340.ref045","first-page":"163","article-title":"Use of visible implant elastomer on two amphibians orders (Anura and Caudata): data on efficiency and reliability","volume":"15","author":"E Lunghi","year":"2015","journal-title":"Atti X Congr Naz Soc Herpetol Ital"},{"key":"pone.0342340.ref046"},{"issue":"11","key":"pone.0342340.ref047","doi-asserted-by":"crossref","first-page":"3255","DOI":"10.3390\/ani11113255","article-title":"Migration and Histologic Effects of Visible Implant Elastomer (VIE) and Passive Integrated Transponder (PIT) Tags in the Marine Toad (Rhinella marina)","volume":"11","author":"ML Cabot","year":"2021","journal-title":"Animals (Basel)"},{"key":"pone.0342340.ref048","doi-asserted-by":"crossref","first-page":"135578","DOI":"10.1016\/j.scitotenv.2019.135578","article-title":"Assessment of microplastics in freshwater systems: A review","volume":"707","author":"C Li","year":"2020","journal-title":"Sci Total Environ"},{"key":"pone.0342340.ref049","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1670\/10-016.1","article-title":"Putting toe clipping into perspective: a viable method for marking anurans","volume":"45","author":"TU Grafe","year":"2011","journal-title":"J Herpetol"},{"issue":"3","key":"pone.0342340.ref050","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1670\/07-265.1","article-title":"Modeling the Effect of Toe Clipping on Treefrog Survival: Beyond the Return Rate","volume":"42","author":"JH Waddle","year":"2008","journal-title":"Journal of Herpetology"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342340","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T18:29:47Z","timestamp":1770748187000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342340"}},"subtitle":[],"editor":[{"given":"Philippe J. R.","family":"Kok","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,2,10]]},"references-count":50,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2,10]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0342340","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,10]]}}}