Herpetological Conservation and Biology
There is increasing interest in the use of unique spot patterns as a way to “mark” individual amphibians as an alternative to invasive techniques for studies of free-ranging populations. however, studies testing the efficacy of the pattern recognition technique have largely drawn their conclusions from the ability to recognize recaptured individuals that were identified solely by spot pattern. individuals whose color pattern changed significantly would therefore not be identified upon recapture. for this study, Tiger salamanders (Ambystoma tigrinum) were captured in west-central Minnesota and maintained in captivity for one year, and their dorsal and ventral surfaces photographed approximately every six weeks. The stability of the spot patterns and their utility as individual identifiers were examined through comparison tests that required the matching of photographs taken 12 months apart. each of the 23 volunteers who took the test was given a sample photograph and asked to choose the corresponding photograph from four others or to choose “no match”. on average, volunteers were able to correctly match the photographs only 67% of the time. four of the salamanders (36%) could be identified by all volunteers, whereas another 36% were matched at a rate that was no better than guessing. Two of these salamanders changed dramatically in appearance, from the spotted A. tigrinum pattern to the blotched A. mavortium melanostictum pattern. The high frequency of misidentifications and the dramatic changes in coloration have implications not only for studies that involve identification of recaptured individuals, but potentially for efforts to classify the different subspecies of Tiger salamanders.
Copyright © 2013. Heather Waye. All Rights Reserved.
Waye, H.L. 2013. Can a tiger change its spots? A test of the stability of spot patterns for identification of individual tiger salamanders (Ambystoma tigrinum). Herpetological Conservation and Biology 8:419-425.