Novel, non-invasive method for distinguishing the individuals of the fire salamander (Salamandra salamandra) in capture-mark-recapture studies

Abstract

Recently we started implementing a highly efficient, non-invasive method of direct individual marking (i.e., typifying) in a population study of the fire salamander, Salamandra salamandra. Our technique is based on the unique alphanumeric code for every individual, generated upon the numbers of openings of repellent/toxic skin glands in the yellow areas of the selected regions of the body. This code was proved reliable in the sample of 159 individuals from two separate populations and enabled easy and quick recognition of recaptured animals. The proposed method is inexpensive, easily applicable in the field, involves minimum stress for the animals and does not affect their behaviour and the possibility of repeated captures of “marked” (i.e., coded) individuals. It is particularly suitable for dense populations.