MOVEMENT PATTERNS IN ELAPHE SCALARIS AT DONANA-NATIONAL-PARK, SOUTHWEST SPAIN

Information on the patterns of movement of adult ladder snakes (Elaphe scalaris) in southwestern Spain is presented. Five adults were radio-equipped with force-fed transmitters. The length of the monitoring period averaged 17.6 +/- 7 days. On average, the snakes were motionless almost 80% of the time. The percentage of mobile days varied with individuals, ranging from 10% to 23.5%. The mean overall length of the sedentary periods was 4.8+/-3.4 days (n = 15). The average length of the movement periods was 1.23 +/- 0.6 days (n = 13). There was no significant difference between individuals or sexes. The mean distance traveled by active day, was 132.8 +/- 36.1 m/day. There was a significant linear relationship between the number of days since release and the distance from the initial to the final location on each monitoring day. Individual E. scalaris did not seem to move within a defined area and did not return to basking or shelter sites. Rather, they tended to wander randomly. Areas of activity (calculated by the minimum convex polygon method) ranged between 0.32 and 4.87 ha.