Torpor and Thermal Adaptations in Mammalian Systems

Mammalian torpor is a controlled state of reduced metabolic rate and lowered body temperature that enables energy conservation during periods of resource scarcity or environmental stress. This capacity for heterothermy ranges from daily torpor in small insectivores and marsupials to prolonged hibernation in larger species, reflecting a spectrum of thermal adaptations shaped by evolutionary and ecological pressures. Underpinning these strategies are adjustments in endogenous heat production—via mechanisms such as non-shivering thermogenesis—and precise regulation of cardiovascular and endocrine systems to support safe entry into and emergence from torpor. Structural traits including fur insulation, subcutaneous fat storage and behavioural tactics such as sun-basking or nest building further augment thermal stability. Research has revealed that torpor not only enhances survival in cold or resource-poor habitats but also confers resilience to unpredictable events such as storms and fires. Beyond ecological importance, insights into mammalian hypometabolism have practical applications in wildlife conservation, climate-change modelling and biomedical fields exploring organ preservation and metabolic suppression. An integrated understanding of torpor and thermal adaptation thus informs both fundamental biology and applied sciences, highlighting the remarkable flexibility of mammalian physiology in the face of environmental fluctuation.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Torpor and Thermal Adaptations in Mammalian Systems publication trend

The graph below shows the total number of articles in torpor and thermal adaptations in mammalian systems across all publications each year (not limited to Nature Index journals).

Technical terms

Torpor: A reversible state of controlled metabolic suppression and body-temperature reduction to conserve energy.

Heterothermy: The ability of an organism to exhibit variable body temperatures rather than maintain a constant level.

Basal Metabolic Rate (BMR): The minimal rate of energy expenditure of an endotherm at rest in a thermoneutral environment.

Non-shivering Thermogenesis (NST): Heat production through metabolic processes, notably in brown adipose tissue, without muscular activity.

Thermoregulatory Behaviour: Actions such as basking, nesting or seeking shade that assist in maintaining optimal body temperature.

References

1. Contrasting physiological responses to habitat degradation in two arboreal mammals. iScience (2021).
2. Snoozing through the storm: torpor use during a natural disaster. Scientific Reports (2015).
3. Solar Radiation during Rewarming from Torpor in Elephant Shrews: Supplementation or Substitution of Endogenous Heat Production?. PLOS ONE (2015).
4. More functions of torpor and their roles in a changing world. Journal of Comparative Physiology B (2017).
5. Responding to the weather: energy budgeting by a small mammal in the wild. Current Zoology (2019).