Individual recognition of amphibians:: Effects of toe clipping and fluorescent tagging on the salamander Plethodon vehiculum

Recognition of individual animals is essential for a wide variety of research and monitoring studies involving amphibians, but little information exists on the effects that marking methods have on survivorship, life history, and behavior. We evaluated toe clipping and subcutaneous injections of a fluorescent-elastomer for individual identification of the western red-backed salamander, Plethodon vehiculum, on Vancouver Island, British Columbia. In the laboratory, no confirmed mortality of marked or unmarked (control) salamanders occurred over 64 weeks. The number of toe clips lost as the result of regeneration increased steadily after 35 weeks postmarking, but few fluorescent marks were lost or misidentified. In the field, we recaptured more fluorescent-marked (60%) than toe-clipped (40%) salamanders from September 1997 to May 1998 but detected no differences in growth or spatial movements. In a second field experiment (27 April to 31 May 1999), toe-clipped salamanders gained less weight in relation to their initial body size than did fluorescent-marked and control salamanders. These data suggest that toe clipping affects the ability of individuals to take full advantage of optimal foraging conditions that prevail in May, which, in turn, might affect the quantity of stored energy reserves required for survival over adverse, dry periods in summer.