Table 2.

Behavioral responses during the snake phase.

Behavioral parameter	Mean	Standard deviation	Description
Average distance from the snake (cm) (Figure 4A)	73.05	18.34	Most animals stayed away from the snake, positioning themselves either in the middle of the cage or further back, close to the nestbox. No animal touched the snake and only a few ventured into the zone proximal to the snake. A small number of animals (n = 3) stayed on top of the nestbox for the majority of the time, the furthest point from the snake.
Locomotion (%) (Figure 4B)	4.38	2.37	In the presence of the snake, most animals spent a relatively small proportion of time in translational movement although no animal was completely immobile during the entire 5-m period. It is worth noting that the animals that showed the greatest reduction of locomotive activity (7 animals) also made no vocalizations.
Stare duration (%) (Figure 4C)	29.24	14.73	Many animals spent nearly a third of the 5-m period staring at the snake with 20% spending more than half their time staring at the snake.
Stare frequency (events) (Figure 4D)	28.78	12.84	A significant positive correlation between stare duration and frequency [Pearson's r = 0.67, p < 0.001] indicate that those that made fewer short duration “looks” at the snake may have been avoiding eye-contact with it.
Head-cock (events) (Figure 4E)	8.39	5.13	This measure was highly variable across individuals as can be seen by the non-normal distribution of the histogram.
Tsik call (events) (Figure 4F)	17.88	27.19	Not all animals displayed this vocalization in the presence of the snake (22% made none). Of those that did, 59% made up to 28 tsik calls, whilst a few (8%) produced 70 or more calls.
Tsik-egg call (events) (Figure 4G)	34.24	34.84	The pattern of tsik-egg calls was similar to that of the tsik calls with some animals making none (14%) whilst a few (18%) made a large number (>70). However, the animals that made a large number of tsik-egg calls didn't necessarily make large numbers of tsik calls and vice versa.