IMPACTS OF TATTOOING AND PIT-TAGGING ON SURVIVAL AND FECUNDITY IN THE ALPINE NEWT (TRITURUS ALPESTRIS)

We investigated the impacts of PIT-tagging and tattooing on survival, condition, and egg laying in Alpine newts (Triturus alpestris) by both field and laboratory experiments. A laboratory experiment made it possible to compare impacts of each marking technique with control groups of unmarked newts. This experiment consisted of a 3 × 3 factorial plan (population, replication, and marking) using 90 individuals of each sex. Neither survival nor body condition were affected by marking. No variation was detected between marking treatments. However, marked females laid significantly more eggs than control females. We assume that such higher reproductive outputs are responses to the stress induced by skin injury by both marking techniques, but this hypothesis remains to be tested. The field experiment consisted of monitoring a newt population in a pond where individuals (n = 121) were marked by either marking technique. No difference in survival or in body condition was detected between marking treatments. Either technique reliably met the requirements of data processing. The present study shows that data obtained with both techniques can be regarded as similarly suitable for estimating population parameters. However, because of better long-term reading reliability, PIT-tagging appears to be the preferred one, provided that body size is sufficiently large to accomodate a transponder.