Variation in animal responses to feeding can be attributed to a variety of ecological factors, including foraging mode and dietary specialization. Specialization often favors species that have traits for exploiting food resources that are rare and that are not commonly shared by dietary generalists. We investigated physiological and behavioral responses to feeding between two snake species with different degrees of mammal feeding specialization: Agkistrodon contortrix (copperheads; a terrestrial species in which adults feed almost exclusively on mammals) and Agkistrodon piscivorus (cottonmouths; a semi-aquatic species feeding less on mammals and primarily on ectothermic prey). We measured metabolic rates (at 20, 25, and 30 °C) and body temperature (Tb) selection of snakes both pre- and post-feeding. Following the consumption of rodent meals, post-feeding energy use was higher in A. piscivorus than A. contortrix at both 25 and 30 °C. After feeding, A. piscivorus maintained body temperatures that were 3–4 °C higher, whereas A. contortrix remained within 1 °C of their pre-feeding Tb. Our results support the contention that dietary specialization leads to potential energetic advantages and that generalist species may change their behavior to offset energy used to digest prey.

中文翻译：

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具有对比饮食和栖息地使用的同盟 Agkistrodon 蛇对摄食的比较能量学和热反应

动物对喂养反应的变化可归因于多种生态因素，包括觅食方式和饮食专业化。专业化通常有利于具有开发稀有食物资源特征的物种，这些特征通常不为饮食通才所共有。我们调查了两种具有不同哺乳动物喂养专业化程度的蛇类对喂食的生理和行为反应：Agkistrodon contortrix（铜头蛇；成年人几乎只以哺乳动物为食的陆生物种）和 Agkistrodon piscivorus（棉口蛇；半水生物种，进食较少）哺乳动物，主要是变温猎物）。我们测量了蛇在喂食前和喂食后的代谢率（在 20、25 和 30°C 下）和体温 (Tb) 选择。食用啮齿动物食物后，在 25 和 30 °C 下，A. piscivorus 的摄食后能量消耗高于 A. contortrix。进食后，A. piscivorus 的体温维持在高出 3–4 °C 的水平，而 A. contortrix 保持在进食前 Tb 的 1 °C 以内。我们的结果支持这样的论点，即饮食专业化会带来潜在的能量优势，而通才物种可能会改变它们的行为以抵消用于消化猎物的能量。