DOES APOSEMATIC COLORATION REDUCE PREDATION RISK IN SNAKES? A SHORT PERIOD EXPERIMENT USING PLASTICINE SNAKE MODELS

Abstract

Aposematism in an anti-predation mechanism that occurs when animals exhibit conspicuous signals, which are often of a contrasting color patterns, to alert potential predators of their unpalatability or toxicity. This study aims to test (in a short period) the effectiveness of aposematic coloration by comparing the predatory attack upon snakes models with and without an alert coloration on the body. To simulate snakes, we made 80 greenish plasticine snake models. Half of the models had a red strip on the dorsal part of the body, imitating an aposematic coloration. The other half of the models had only a greenish tint. The models were exposed to predators for 12 hours in an area with countryside vegetation.. Among the 20 models showing signs of predation, 65% were purely greenish models and 35% were models with red coloration on the back. Attaks at extremities (head and tail) were meaningly more frequent on models with red coloration. Our results suggest the efficiency of red coloration as a warning sign and anti-predation mechanism, since the models with red coloration, imitating aposematic preys, were less preyed and were attacked preferentially at the extremities, which suggests caution by the predator.