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How does a reptile’s low metabolic rate affect how much food it needs?

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A painted turtle (Chrysemys picta) with a dark shell and red and yellow markings rests on a rock near water, surrounded by green aquatic plants. — reptile Painted turtle (*Chrysemys picta*).

Because reptiles are ectothermic—relying on external heat sources rather than generating their own internally—they possess a naturally low metabolic rate compared to warm-blooded animals of similar size.12

This low metabolic rate significantly reduces their caloric requirements, as they do not need to burn calories to maintain a constant internal body temperature. Consequently, reptiles require less food than endothermic animals like mammals and birds. This energy-efficient lifestyle is highly advantageous, allowing reptiles to survive in environments where food resources are scarce and to endure long periods without eating.13