Strategies of temperature regulation: effect on evaporation in East African ungulates.

TAYLOR, C. RICHARD. Strategies of temperature regulation. ej’ect on evaporation in East African ungulates. Am. J. Phyisol. 2 19(4) : 1131-l 135.1970.-A number of African ungulates can survive in hot deserts without drinking. Two strategies of temperature regulation are used to reduce evaporation when water intake is restricted. The first is found in large animals, such as the eland (adults may weigh 150-1,000 kg). They have a low body temperature in the morning (as low as 32.8 C) and warm slowly during the day. In this way they may never need to increase evaporation for heat dissipation. The second is found in small animals, such as Grant’s gazelle (adults may weigh 10-50 kg). They warm quickly to very high body temperatures (as high as 42.0 C) which exceed air temperatures of 40 C and neither pant nor sweat. The oryx, a desertdwelling antelope of intermediate size (adults may weigh 70-300 kg), utilizes a combination of both methods. A simulated desert of 12 hr per day at 40 C alternating with 12 hr at 22 C was used for investigating these strategies.