Visible Implant Elastomer Marking Does Not Affect Short-term Movements or Survival Rates of the Treefrog Litoria rheocola

Abstract

Many recent amphibian studies have involved marking individuals using visible implant elastomer (VIE), but the effects of VIE on the movements or survival of amphibians in the wild are unknown. Our aim was to determine if VIE marking influenced the movement distances and survival rates of Common Mistfrogs (Litoria rheocola) in the wild over the 3-wk period following application when effects from handling and marking might be strongest. We used harmonic direction finding to track adult frogs that were either unmarked or marked with VIE, and compared their movement distances, probability of movement, and survival estimates. To account for any effects of the external tracking tags on frog survival, we also estimated survival rates for frogs that were not tracked, but were marked and recaptured at the same site during the same time period. We found no effects of VIE marking on distances moved by frogs or the probability of movement. For tracked frogs, estimated daily survival rates for marked frogs were slightly, but not significantly, higher than those for unmarked frogs. Estimated survival rates were similar between marked frogs that were tracked and marked frogs that were not tracked, suggesting that tracking tags did not influence survival during our study. Of tracked frogs, individuals that were marked had 12.4% higher recapture rates than unmarked individuals. Overall, we found that VIE had minimal effects on movements and survival of frogs over the 3-wk period immediately after marking.