Chapter 1, The Reptilian Spectacle - UWSpace - University of ...

2.3 Results
2.3.1 Spectacle blood flow in undisturbed snakes
During the initial 30 minutes of the trials, when snakes were at rest and undisturbed, significant
differences were found between the durations of flow (M = 57 s, SD = 49 s) and empty periods (M =
115 s, SD = 80 s) when data from all snakes were pooled (p < 0.000). Generally, durations of flow
were shorter than empty periods (see Table 2-1). Differences between individual snakes were seen in
the durations of flow periods (p = 0.006), but not in empty periods (p = 0.640). In the cases of both
flow period and empty period durations, there were differences between trials (p(flow duration) = 0.000; p
(empty duration) = 0.017), suggesting significant variation from day to day. The means and standard
deviations of flow and empty periods for all subjects are tabulated in Table 2-1. Figure 2-6 (next page)
is a graphical representation of spectacle blood flow and empty periods over the initial 30 undisturbed
minutes during two trials in separate snakes. A video recording of the onset and cessation of spectacle
blood flow in a coachwhip snake is available in Appendix A.
Flow (s) Empty (s)
Mean SD Min Max Mean SD Min Max
Snake 1 47 17 12 114 130 71 44 490
Snake 2 66 42 13 214 116 91 7 399
Snake 3 59 68 7 458 101 76 12 360
Table 2-1: Durations of spectacle blood flow and empty periods while undisturbed. The means,
standard deviations, minima and maxima are shown for each experimental subject taken from all 7
trials.
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