The Herpetological Journal

pp. 133-140
Authors: Bainbridge, Loren; Stockwell, Michelle; Valdez, Jose; Klop-Toker, Kaya; Clulow, Simon; Clulow, John & Mahony, Michael

Abstract: Population demographics for amphibian larvae are rarely estimated due to marking technique limitations on small body size, morphological change (metamorphosis), and the associated habitat changes (aquatic to terrestrial environments). A technique that may meet some of these limitations is visible implant elastomer (VIE) tagging. In this study, we report on the efficacy of VIE tagging a tree frog (Hylidae) at the tadpole stage for cohort identification across metamorphosis to the adult stage, in a field environment. During our preliminary captive trial, post-metamorphosis tag retention was 100% over three months, with no adverse effects observed on survival, growth or time to metamorphosis. During our field study tag retention in recaptured Litoria aurea was 95% for tadpoles and 88% across metamorphosis. By 200 days post-tagging, retention declined to 75% in the adult stage and stabilised around 50% by 300 days. Post metamorphosis the retention rate was less reliable and dependent upon sex and life-stage. Females showed the highest retention rate (max. 62%, 760 days post tagging), followed by juveniles (max. 45%, 400 days post tagging) and males (max. 20%, 760 days post tagging). We conclude that VIE tagging is a viable method for studying cohort larval movements and population demographics of amphibians up to a 50 day post-metamorphosis stage.

Keywords: LITORIA AUREA, METAMORPHOSIS, TADPOLE, VIE TAGGING, TAG RETENTION