THE EFFECT OF SURGICALLY IMPLANTED TRANSMITTERS UPON THE LOCOMOTORY PERFORMANCE OF THE CHECKERED GARTER SNAKE, THAMNOPHIS-M-MARCIANUS

The effect of both surgery and implanted transmitters upon sprint time of Thamnophis m. marcianus from two populations was assessed under la boratory conditions using a circular racetrack. The mean sprint times of snakes before surgery were 7.52 s (SE = 0.393, n = 8) and 9.69 s (S E = 0.358, n = 5) for the Arizona and Texas populations, respectively. Mean sprint times of the same snakes following surgery were 7.55 s (S E = 0.387, n = 8) for the Arizona population and 9.83 s (SE = 0.408, n = 5) for the Texas population. A repeated measures ANOVA indicated th at sprint time for both non-surgery and surgery treatments did not dif fer significantly. Transmitter treatments consisted of implanting tran smitters equalling 10% or 15% of the snake's body mass. The mean sprin t times for snakes receiving either 10% or 15% transmitter treatments were statistically compared to the mean sprint time of snakes receivin g the surgery treatment. A two-way ANCOVA accounting for body mass ind icated that the mean sprint time was significantly reduced for snakes carrying implanted transmitters equal to 15% of their body mass. These results suggest that surgical techniques have no effect upon locomoto ry performance and that implanted transmitters for radiotelemetry of s nakes should probably not exceed 10% of the snake's body mass.