文獻來源: Cadena V, Tattersall GJ. 2009. The Effect of Thermal Quality on the Thermoregulatory Behavior of the Bearded Dragon Pogona vitticeps: Influences of Methodological Assessment. Physiological and Biochemical Zoology 82(3):203–217. 2009. DOI: 10.1086/597483.
Abstract
Metabolic functions are generally optimized within a narrow range of body temperatures (Tb's), conferring thermoregulation great importance to the survival and fitness of an animal. In lizards, Tb regulation is mainly behavioral, and the metabolic costs associated with behavioral thermoregulation are primarily locomotory. In reptiles, however, it has been proposed that they thermoregulate less precisely when the associated costs, metabolic or otherwise, are high. Such a strategy enhances fitness by allowing lizards to be more flexible to changing environmental conditions while maximizing the benefits of maintaining a high Tb and minimizing energy expenditure. We evaluated the behavioral thermoregulation of inland bearded dragons Pogona vitticeps under various thermal quality conditions requiring different locomotory investment for thermoregulation. The selected ambient temperature and preferred Tb ranges increased at lower environmental thermal qualities, indicating a decrease in thermoregulatory precision in environments where the costs associated with thermoregulation were high. The level of thermoregulation was also affected, exhibiting a decrease in preferred Tb of 2°C at the lowest‐thermal‐quality treatment. These data provide important implications for the procedural assessment of preferred Tb and a better understanding of thermal set points in reptiles in general. Our results emphasize that the precise maintenance and assessment of preferred Tb is contingent on the quality of the environment, laboratory or natural, that the animal inhabits.
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Abstract
Metabolic functions are generally optimized within a narrow range of body temperatures (Tb's), conferring thermoregulation great importance to the survival and fitness of an animal. In lizards, Tb regulation is mainly behavioral, and the metabolic costs associated with behavioral thermoregulation are primarily locomotory. In reptiles, however, it has been proposed that they thermoregulate less precisely when the associated costs, metabolic or otherwise, are high. Such a strategy enhances fitness by allowing lizards to be more flexible to changing environmental conditions while maximizing the benefits of maintaining a high Tb and minimizing energy expenditure. We evaluated the behavioral thermoregulation of inland bearded dragons Pogona vitticeps under various thermal quality conditions requiring different locomotory investment for thermoregulation. The selected ambient temperature and preferred Tb ranges increased at lower environmental thermal qualities, indicating a decrease in thermoregulatory precision in environments where the costs associated with thermoregulation were high. The level of thermoregulation was also affected, exhibiting a decrease in preferred Tb of 2°C at the lowest‐thermal‐quality treatment. These data provide important implications for the procedural assessment of preferred Tb and a better understanding of thermal set points in reptiles in general. Our results emphasize that the precise maintenance and assessment of preferred Tb is contingent on the quality of the environment, laboratory or natural, that the animal inhabits.
圖片連結: davidwallphoto.com