Metabolic rate and body temperature reduction during hibernation and daily torpor.

  title={Metabolic rate and body temperature reduction during hibernation and daily torpor.},
  author={Fritz Geiser},
  journal={Annual review of physiology},
  • F. Geiser
  • Published 11 February 2004
  • Biology
  • Annual review of physiology
Although it is well established that during periods of torpor heterothermic mammals and birds can reduce metabolic rates (MR) substantially, the mechanisms causing the reduction of MR remain a controversial subject. The comparative analysis provided here suggests that MR reduction depends on patterns of torpor used, the state of torpor, and body mass. Daily heterotherms, which are species that enter daily torpor exclusively, appear to rely mostly on the fall of body temperature (Tb) for MR… 

Figures and Tables from this paper

Metabolic Rate Reduction During Hibernation and Daily Torpor

Most of the apparently contradictive hypotheses that have been proposed to explain metabolic rate reduction appear to be correct, however, not all hypotheses match the measured data of all species in all stages of torpor.

Pronounced differences in heart rate and metabolism distinguish daily torpor and short-term hibernation in two bat species

Torpor, and its differential expression, is essential to the survival of many mammals and birds. Physiological characteristics of torpor appear to vary between those species that express strict daily

Metabolic Rate and Body Temperature Reduction during Hibernation

It has been found that metabolic rate, once affected by temperature, will affect the temperature during hibernation as a regulatory control and the reduction of the metabolic rate and body temperature occurs as an energy saving mechanism during unfavorable conditions.

Mitochondrial metabolism in hibernation and daily torpor: a review

Respiratory suppression depends on in vitro assay temperature (no suppression is evident below ~30°C) and (at least in hibernation) dietary polyunsaturated fats, suggesting effects on inner mitochondrial membrane phospholipids.

Daily torpor and hibernation in birds and mammals

  • T. RufF. Geiser
  • Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2015
The analysis strongly supports the view that hibernators and daily heterotherms are functionally distinct groups that probably have been subject to disruptive selection.


  • F. Geiser
  • Environmental Science
    Current Biology
  • 2013

Seasonal Control of Mammalian Energy Balance: Recent Advances in the Understanding of Daily Torpor and Hibernation

Recent advances in the understanding of energy balance and its neuronal and endocrine control during the most extreme metabolic fluctuations in nature: daily torpor and hibernation are focused on.

Hibernation and daily torpor in Australian mammals

Daily and prolonged torpor in many Australian mammals appear to be opportunistic and not only important for survival of adverse seasonal conditions, but apparently also for dealing with unpredictable events such as droughts and perhaps fires and floods.

Hibernation and daily torpor minimize mammalian extinctions

Evidence is provided that almost all (93.5%) of 61 recently extinct mammal species were homeothermic, maintaining a constant high body temperature and thus energy expenditure, which demands a high intake of food, long foraging times, and thus exposure to predators.

Torpor and hypothermia: reversed hysteresis of metabolic rate and body temperature.

Clear diagnostic physiological differences between these two states are demonstrated that can be used experimentally to confirm whether torpor or hypothermia has occurred and can clarify the results of studies investigating the ability of physiological or pharmacological agents to induce torpor.

Perspectives on Metabolic Suppression during Mammalian Hibernation and Daily Torpor

A different experimental approach is proposed which could allow direct comparison of minimum MR at the same Tb during hibernation and induced hypothermia and hopefully will resolve if active inhibition of MR is indeed a state-dependent characteristic of torpor and hibernation.

Reduction of metabolism during hibernation and daily torpor in mammals and birds: temperature effect or physiological inhibition?

  • F. Geiser
  • Biology
    Journal of Comparative Physiology B
  • 2004
Findings show that the reduction in metabolism during torpor of daily heterotherms and large hibernators can be explained largely by temperature effects, whereas a metabolic inhibition in addition to temperature effects may be used by small hibernator to reduce energy expenditure during torpora.

Relationships between body temperature, thermal conductance,Q10 and energy metabolism during daily torpor and hibernation in rodents

It is suggested that the changes inC' represent a suite of physiological adaptations that have played a central role in the evolution of torpor, enabling rodents to regulateTB aboveTB during periods of very low heat production.


It is reviewed whether circadian and circannual rhythms, important in the timing of biological events in active animals, also play an important role during torpor when Tb is reduced substantially and may even fall below 0°C, and there is little evidence it is significantly affected by low Tb.

Respiratory Exchange and Ventilation during Nocturnal Torpor in Hummingbirds

It is concluded that a normal Q10 effect is sufficient to explain the metabolic rate of torpid hummingbirds and that transient CO₂ storage may occur during entrance into torpor but is not a prerequisite for entrance.

Hibernation versus Daily Torpor in Mammals and Birds: Physiological Variables and Classification of Torpor Patterns

Comparisons of several physiological variables appear to justify a distinction between the two torpor patterns, but of all variables tested, only the frequency distributions of maximum torpor bout duration and the minimum V̇o2 showed a clear gap between daily heterotherms and hibernators.

Reduction of metabolic rate and thermoregulation during daily torpor

Over the air temperature range in which body temperature of S. macroura was not metabolically defended, metabolic rate during daily torpor was largely a function of body temperature, and even in thermoregulating animals, the reduction of metabolic rate from normothermia to torpor at a given air temperature can also be explained by temperature effects.

The effect of He−O2 exposure on metabolic rate, thermoregulation and thermal conductance during normothermia and daily torpor

Recently it was proposed that the low metabolic rate during torpor may be better explained by the reduction of thermal conductance than the drop of body temperature or metabolic inhibition. We tested

Daily Torpor and Thermoregulation in the Small Dasyurid Marsupials

Torpor in endotherms has only been observed in small species, suggesting that body mass determines the occurrence of torpor. The present study investigates the influence of body mass on the

The effect of temperature on the pattern of torpor in a marsupial hibernator

Investigation of how changes in air temperature affect the duration of torpor bouts, metabolic rate, body temperature and weight loss of the marsupial hibernator Burramys parvus found a change in climate would most likely increase winter mortality of this endangered species.