Deliberate tail loss in Dolichophis caspius and Natrix tessellata (Serpentes: Colubridae) with a brief review of pseudoautotomy in contemporary snake families

Abstract

Deliberate tail loss was recorded for the first time in three large whip snakes (Dolichophis caspius) and one dice snake (Natrix tessellata). Observations were made in different years and in different locations. In all cases the tail breakage happened while snakes were being handled by researchers. Pseudoautotomy was confirmed in one large whip snake by an X-Ray photo of a broken piece of the tail, where intervertebral breakage was observed. This evidence and literature data suggest that many colubrid species share the ability for deliberate tail loss. However, without direct observation or experiment it is not possible to prove a species' ability for pseudoautotomy, as a broken tail could also be evidence of an unsuccessful predator attack, resulting in a forcefully broken distal part of the tail.