A Method of Marking Living Snakes for Future Recognition, with a Discussion of Some Problems and Results

Abstract

Several years ago, during certain studies on the habits of snakes, it was realized that some simple system for recognizing individuals must be devised. In working with ring-neck snakes, Diadophis punctatus edwvardsii, complete scale counts and measurements had been made, the snakes had then been released, and collecting had been done in subsequent years in the vicinity of release. It was found, however, that identical scutellation alone was insufficient to establish identity when snakes were recaptured. Later, individual peculiarities were recorded, as well as the scale counts, so that the identity of returns could be absolutely established. But to carry out the work on an extensive scale by this method is too laborious, involving, as it does, a complete counting of the scales each time that the snake must be identified. Yet, only by conducting the work on a somewhat extensive scale could sufficient data be obtained for satisfactory conclusions on the problems involved. One of the studies in which was felt the need of marks for identification was on the rate of growth of snakes under natural conditions. This led to questions on the rate of growth at different ages and at different times of the year, of the relation of age to size, and of the length of life of the individual and the usual length of life in the species. Another study for which identification of individuals was necessary was that of the home of an individual snake, or the extent of its wanderings. Closely connected with this is the question of the effect of transporting a snake from its home range to a distant point. The possibility, or even probability, of determining something about the snake population of a region was also realized. These questions and others may be successfully investigated if there is available a suitable system of marking individuals. Marks are necessary wherever it is desired to keep several or many snakes in the same enclosure, and yet to be able to recognize individuals quickly, as is the case in breeding studies which the senior author is conducting at Ann Arbor, Michigan.