Is physiological performance optimized by thermoregulatory behavior?:: a case study of the eastern fence lizard, Sceloporus undulatus

Eastern fence lizards (Sceloporus undulatus) exhibit a distinct thermal preference that might be related to the thermal optimum for physiological performance. Sprint speed and treadmill endurance of S. undulatus were insensitive to body temperature in the ranges of 28-38degreesC and 25-36degreesC. respectively. Both locomotor and digestive performances are optimized at the preferred body temperature of S. undulatus. but thermoregulatory behavior is more closely related to the thermal sensitivity of digestive performance than that of locomotor performance. (C) 2002 Elsevier Science Ltd. All rights reserved.