Visual implant elastomer (VIE) tags are an unreliable method of identification in adult anurans

摘要

There has long been debate over alternatives to toe-clipping as an individual marking method in anurans. Alternative methods include visible implant elastomer (VIE) tags and passive integrated transponder (PIT) tags. VIE tags are low cost, easy to insert and have been used successfully in reptiles, fish and salamanders without tag loss or movement. In this study, we tested whether two species of VIE-tagged anurans (captive Kihansi spray toads, Nectophrynoides asperginis, and leopard frogs Lithobates pipiens) experienced tag movement or loss that could lead to errors in individual identification. VIE tag movement occurred in 50% of the tags implanted which caused 70.6% of individuals to be potentially misidentified. These results demonstrate that the use of VIE tags to individually mark anurans can be highly unreliable. We therefore recommend either verifying the reliability of VIE tags through species- and life stage-specific pilot studies, or choosing another method of marking.