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Why do many Arctic mammals have large bodies despite the severe cold?
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Polar ecosystem
Southern limit of Arctic tundra and approximate line of demarcation between Low and High Arctic.
Many Arctic mammals possess large bodies as an adaptive mechanism to survive in severe cold, a principle known as Bergmann’s Rule.
This biological principle states that within a wide-ranging species, individuals in colder regions tend to be bulkier than those in warmer regions. The primary advantage of this increased body size is the reduction of the surface-area-to-weight ratio. By having a larger mass relative to their surface area, these animals are better able to conserve internal body heat, which is essential for survival in freezing climates.12