Evaporative water loss: thermoregulatory requirements and measurements in the deer mouse and white rabbit
Tóm tắt
Using a physical model of the capacity for non-evaporative heat loss and measurements of metabolic heat production, I evaluated the evaporative requirements for thermoregulation in the deer mouse,Peromyscus maniculatus, and the white rabbit,Oryctolagus cuniculus. The physical limit to non-evaporative heat loss was calculated from the heat transfer properties of the two animals and expressed as a maximum thermal conductance (C
max). Two physiologically-based thermal conductances were derived from evaporative water loss, respiratory gas exchange and core temperature measurements made between 8 and 34°C on the deer mouse, and taken from published data for the white rabbit. The thermal conductance for non-evaporative heat loss (C) was calculated from net heat production, whereasC
m represented the thermal conductance required to dissipate metabolic heat production. Evaporation is required when metabolic heat production exceeds the capacity for non-evaporative heat loss (as shown byC
m>C
max). However, evaporation increased in both animals although additional capacity to lose heat remained (i.e.,C
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