Synergistic effects of musking and autohaemorrhaging on the duration of death feigning in dice snakes (Natrix tessellata)

Predation exerts a significant selection pressure on prey, shaping a multitude of traits that serve as antipredator defences. In turn, natural selection could favour combinations of antipredator defences with synergistic effects that enhance prey survival. An especially interesting antipredator defence is death feigning (DF), present in a wide variety of taxa and usually characterized by the prey lying motionless often along with defaecation, musking and autohaemorrhaging (AH). All these aspects of the DF display should work in conjunction with one another, intensifying the overall effect of the display and in turn facilitating quicker escape. To confirm this hypothesis, we tested 263 dice snakes (Natrix tessellata) directly in the field. We noted the occurrence of smearing faeces, musk and AH, and we measured the duration of DF, expecting to see a negative association between the occurrence of these behaviours and the duration of DF. Our results affirm our hypothesis: dice snakes that smeared themselves in musk and faeces prior to DF and had AH during DF spent significantly less time in DF. Our results highlight the functional integration of antipredator behaviours across different phases of predator-prey interactions, emphasizing the need for future research to prioritize studying the sequential display of behaviours.