Environmental Temperatures and Activities in Wild Spotted Turtles, Clemmys guttata

Abstract

Cloacal and environmental temperatures of 512 wild spotted turtles, Clemmys gut- tata, from southeastern Pennsylvania were recorded during various phases of their normal activities: basking, feeding, moving in water or on land, dormant in water of both high and low temperatures, and courtship, mating and nesting. The mean cloacal temperature for activity was calculated as approximately 20.16?C and the normal activity range 3-32?C. Cloacal temperatures were closely correlated to those of the environment during all activities. Males fed and were otherwise more active than females in waters of cooler temperatures (P < 0.05), but this was probably due to females remaining active longer into the warmer parts of the annual cycle. Clemmys guttata are often active at water temperatures of about 5?C in early spring. They become dormant when water temperatures reach about 30?C in June, and also shift their diel activity cycle from afternoon to morning as summer approaches. Feeding begins when water temperatures reach 14?C. Reproductive activity may occur at cloacal temperatures as low as 8?C in water of 8.5?C. Clemmys guttata behaviorally thermoregulate by basking in cooler weather, and by burrowing into the soft bottom of a waterway or entering muskrat burrows and lodges to avoid extreme hot and cold conditions.