Synergistic effects of musking and autohemorrhaging 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 defecation, musking, and auto-haemorrhaging. All these aspects of DF 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 and musk and autohaemorrhaging 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..., Fieldwork was performed at Golem Grad Island (40°52′08′′ N, 20°59′23′′ E, Prespa Lake, North Macedonia). We searched for dice snakes in the open or sheltered under natural cover and quickly captured them by hand. At capture, each snake (N=263) was always grabbed approximately at mid-body with one hand since it has been previously shown that holding snakes at different parts of the body elicits drastically different behavioural responses.
During the first 30 seconds after capture, while holding the snake in the air, we noted the occurrence of smearing. Smearing was defined as the snake expelling the contents of the cloacal glands and defecating while at the same time using the tail to smear musk and faeces on its body. This was termed as the “capture test”. All authors captured the snakes and observed the occurrence of smearing as it was easily observable.
Immediately after the capture test, we performed the “post-capture test”, which included a series of generalized predator-like action..., , # Synergistic effects of musking and auto-hemorrhaging on the duration of death feigning in dice snakes (*Natrix tessellata*)

[https://doi.org/10.5061/dryad.3tx95x6ph](https://doi.org/10.5061/dryad.3tx95x6ph)

The database contains two sheets with one (titled “data”) being used to perform the statistical analyses and the other one (titled “graph”) was used to produce Figure 2. The columns in the data sheets are as follows:

### Sheet “data”

* Smearing – occurrence of smearing as a capture behaviour (yes/no)
* Recovery – duration of DF (in seconds). Individuals that did not exhibit DF have these cells left blank to not interfere with the accompanying code.
* DF – occurrence of DF (yes/no)
* AH – occurrence of AH (yes/no)
* Temperature – cloacal temperatures of tested snakes (in °C)
* SVL – snout-to-vent lengths of tested snakes (in cm)
* Sex – sex of the tested snakes (males/females)
* Age – age category of tested snakes (adult/juvenile)
* State – variable that includ...