A model of the energy budget for the wandering garter snake (Thamnophis elegans vagrans) was constructed from equations describing heat flows at the animal's skin surface and body core. A new method was developed for expressing the role of heat transfer from the substrate in influencing body temperature. Convection coefficients were evaluated on live snakes in a wind tunnel and determined to be essentially identical to those for cylinders. Climate space diagrams were generated from energy budget equations for snakes in their natural montane habitats at 2600 m in Larimer County, Colorado. The attainable body temperatures revealed by climate space diagrams show that the physical environments normally encountered by T. elegans are surprisingly harsh. For example, in July the maximum voluntary body temperature (35@?C) would be exceeded in open microhabitats (bare ground, rocks, grass) for @?5.5-6 h of each clear day. Optimum body temperatures (26-32@?C) could be attained for only @?1.5-2.5 h each day, and the critical thermal maximum would be exceeded for at least 3 h in bare-ground or rock microhabitats. On cool or cloudy days in May and September, a snake could barely attain the minimum optimum body temperature in any microhabitat.
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文章 : 英语