Defensive behavior of free-ranging pygmy rattlesnakes (Sistrurus miliarius)

Sistrurus miliarius frequently bites humans in the southeastern United States. We used a large population of S. miliarius in central Florida to investigate the importance of several factors on the defensive behavior of this species. Upon detection of a snake, we tapped the snout of the snake with a gloved hand. We recorded whether the snake struck or fled. Our large sample size (N = 336) allowed its to make strong conclusions regarding the defensive behavior of this rattlesnake species. Overall, only 27 snakes (8%) bit the glove indicating that this species is rather nonaggressive. Initial posture was the only factor that influenced striking behavior; uncoiled snakes struck significantly more than coiled snakes. Fleeing behavior was affected by three variables: sex; whether the snake was about to shed; and initial posture. Females fled more often than males, as did snakes about to shed. Initial posture is the only factor that affected both response variables, and uncoiled individuals were more likely to flee than coiled snakes.