Table 3.
Analysis of covariance (ANCOVA) models for quantitative antipredator behaviors of mainland (N = 20) and Santa Catalina Island (N = 10), California, USA, populations of the southern Pacific rattlesnake (Crotalus helleri).
| Variables a | F-Value b | p-Value | Partial η2 |
|---|---|---|---|
| Latency to capture (s) | |||
| Population | 16.62 | <0.001 | 0.39 |
| Snake length | 0.88 | 0.358 | 0.03 |
| Duration captivity | 0.33 | 0.573 | 0.01 |
| Venom expended (mg) | |||
| Population | 11.64 | 0.002 | 0.33 |
| Snake length | 13.62 | 0.001 | 0.36 |
| Duration captivity | 0.54 | 0.472 | 0.02 |
| Bilateral venom pulses (number) | |||
| Population | 1.99 | 0.172 | 0.08 |
| Snake length | 0.04 | 0.843 | 0.00 |
| Duration captivity | 0.00 | 0.994 | 0.00 |
| Venom per bite (mg) | |||
| Population | 7.31 | 0.012 | 0.23 |
| Snake length | 12.07 | 0.002 | 0.34 |
| Duration captivity | 0.01 | 0.922 | 0.00 |
a One snake refused to deliver venom; thus, for the three venom variables, N = 19 and 9 for mainland and Santa Catalina Island populations, respectively. b df = 1.26 for the latency to capture model, and df = 1.24 for the three venom models.