Photographic identification of sea turtles: method description and validation, with an estimation of tag loss

Recognition of individual sea turtles is mostly achieved by checking artificial tags previously attached to them, a method which is made difficult by the considerable tag loss rate and which requires repeated manipulation of the marked individuals. We describe an individual recognition method for se...

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Detalhes bibliográficos
Autores: Reisser, Júlia Wiener, Proietti, Maíra Carneiro, Kinas, Paul Gerhard, Sazima, Ivan
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:Brasil
Recursos:Universidade Federal do Rio Grande (FURG)
Repositorio:Repositório Institucional da FURG (RI FURG)
Idioma:inglés
OAI Identifier:oai:repositorio.furg.br:1/917
Acesso em linha:http://repositorio.furg.br/handle/1/917
Access Level:acceso abierto
Palavra-chave:Photo-identification
Sea turtles
Cheloniidae
Tag loss
Bayesian inference
Descrição
Resumo:Recognition of individual sea turtles is mostly achieved by checking artificial tags previously attached to them, a method which is made difficult by the considerable tag loss rate and which requires repeated manipulation of the marked individuals. We describe an individual recognition method for sea turtles of the family Cheloniidae based on a mark-recapture study that relied on both artificial tagging (Inconel tags, style 681) and natural marks (facial profile photographs). Juvenile green Chelonia mydas and hawksbill Eretmochelys imbricata turtles were manually caught at Arvoredo Island, southern Brazil, and through visual comparison of facial profile photographs we were able to identify recaptured individuals with 2, 1, or no artificial tags. Additionally, Bayesian inference based on tag loss information indicated that the way a tag is attached (position and distance from the flipper edge) affects significantly the probability of its loss. We encourage the use of photographic identification (facial profile) as a reliable method for individual recognition in studies of cheloniid turtles.