The strange animals that control their body heat

Scientists are discovering that many mammals possess a remarkable biological capability called heterothermy, allowing them to intentionally fluctuate their body temperature as an energy-saving survival mechanism. While humans maintain a stable 98.6°F through homeothermy, animals like the fat-tailed dwarf lemur can vary their temperature by 45°F within a single day, and Australian eastern long-eared bats enter torpor states in response to weather changes. This flexible approach represents a spectrum from brief shallow torpor to deep hibernation, challenging the long-held assumption that most mammals maintain constant body temperatures like humans do.

Recent technological advances in tracking small animals have revealed these capabilities in surprising contexts. Sugar gliders were observed dropping their body temperature from 94.1°F to approximately 66°F during cyclones, while pregnant hoary bats can pause their pregnancies during spring storms. Researchers like Danielle Levesque at University of Maine note this 'weirdness' was previously underestimated because monitoring technology couldn't capture these subtle metabolic shifts in wild populations. The findings suggest torpor serves multiple functions beyond winter survival, including weather adaptation and reproductive timing control.