One step forward: contrasting the effects of Toe clipping and PIT tagging on frog survival and recapture probability

Abstract

Amphibians have been declining worldwide and the comprehension of the threats that they face could be improved by using mark–recapture models to estimate vital rates of natural populations. Recently, the consequences of marking amphibians have been under discussion and the effects of toe clipping on survival are debatable, although it is still the most common technique for individually identifying amphibians. The passive integrated transponder (PIT tag) is an alternative technique, but comparisons among marking techniques in free-ranging populations are still lacking. We compared these two marking techniques using mark–recapture models to estimate apparent survival and recapture probability of a neotropical population of the blacksmith tree frog, Hypsiboas faber. We tested the effects of marking technique and number of toe pads removed while controlling for sex. Survival was similar among groups, although slightly decreased from individuals with one toe pad removed, to individuals with two and three toe pads removed, and finally to PIT-tagged individuals. No sex differences were detected. Recapture probability slightly increased with the number of toe pads removed and was the lowest for PIT-tagged individuals. Sex was an important predictor for recapture probability, with males being nearly five times more likely to be recaptured. Potential negative effects of both techniques may include reduced locomotion and high stress levels. We recommend the use of covariates in models to better understand the effects of marking techniques on frogs. Accounting for the effect of the technique on the results should be considered, because most techniques may reduce survival. Based on our results, but also on logistical and cost issues associated with PIT tagging, we suggest the use of toe clipping with anurans like the blacksmith tree frog.

Comparison of photo‐matching algorithms commonly used for photographic capture–recapture studies

“…Capture–mark–recapture (CMR) and capture–recapture (CR) models have proven to be very useful for estimating population demography and for testing ecological hypotheses (Cormack, ; Jolly, ; Lebreton, Burnham, Clobert, & Anderson, ; Seber, ). CMR studies typically require invasive techniques (e.g., tags, toe‐clipping, visual implant elastomers, or insertion of passive integrated transponders) (Bailey, ; Guimarães et al., ; Winandy & Denoël, ). However, these invasive approaches can be cost prohibitive to implement and could potentially affect individual behavior or survival (Wilson & McMahon, ).…”

Effectiveness of phalanx skeletochronology to estimate age in living reptiles

“…Moreover, it should be noted that toe clipping with proper disinfection does not decrease survival (Mccarthy & Parris, 2004;Grafe et al, 2011;Guimarães et al, 2014). The fact that age was equally well estimated with any phalanx number implies that the toe used is irrelevant.…”

“…Sinsch et al, 2002;Grafe et al, 2011;Dubey et al, 2013). Clipping of one or two toes does not significantly reduce survival (Mccarthy & Parris, 2004, Grafe et al 2011Guimarães et al, 2014). Moreover, cutting phalanges has no significant effects on key traits of animal behaviour, such as sprint speed (Huey et al, 1990;Husak, 2006).…”

Treefrog lateral line as a mean of individual identification through visual and software assisted methodologies

“…One of the most frequently used method is toe-clipping because of its easy and inexpensive use (Donnelly et al, 1994, Waichman 1992. However, its use is currently debated as an invasive method, potentially causing infections and altering behaviors, especially for small species like hylids (Clarke 1972, Golay and Durrer 1994, Lemckert 1996, Waddle et al 2008, Guimaraes et al 2014. As a result, the environmental administration of the Federative Republic of Brazil has considered a ban on toe-clipping (Corrêa 2013).…”