Fat and fed: frequent use of summer torpor in a subtropical bat

  title={Fat and fed: frequent use of summer torpor in a subtropical bat},
  author={Clare Stawski and Fritz Geiser},
A widely held view is that torpor is avoided by mammals whenever possible because of potential costs associated with reduced body temperatures and slowed metabolic processes. We examined this hypothesis by quantifying use of torpor in relation to body condition of free-ranging northern long-eared bats (Nyctophilus bifax, approximately 10 g), a species known to hibernate, from a subtropical region during the austral summer when insects were abundant. Temperature-telemetry revealed that bats used… 
Nightly torpor use in response to weather conditions and individual state in an insectivorous bat
This work investigates how weather conditions affect nightly torpor patterns in the nocturnal insectivorous Australian eastern long-eared bat and suggests that bats evaluate multiple environmental cues to make decisions regarding torpor use versus active foraging based upon their expectations of the energetic benefits, prey availability and relative predation risk.
Torpor and activity in a free-ranging tropical bat: implications for the distribution and conservation of mammals?
It is proposed that the ability of employing torpor and the resulting highly plastic energy requirements may partially explain why these small insectivorous bats can inhabit almost the entire Australian continent despite vastly different climatic and likely trophic conditions.
Some like it cold: summer torpor by freetail bats in the Australian arid zone
It is demonstrated that this desert bat uses torpor extensively in summer and often rewarms passively from torpor to maximise energy and water conservation.
Hibernation and torpor in tropical and subtropical bats in relation to energetics, extinctions, and the evolution of endothermy.
It is likely that torpor, highly effective in reducing requirements for energy and water even under warm conditions, plays a crucial role in the long-term survival of the majority of small tropical and subtropical bats.
Do season and distribution affect thermal energetics of a hibernating bat endemic to the tropics and subtropics?
  • C. Stawski, F. Geiser
  • Environmental Science
    American journal of physiology. Regulatory, integrative and comparative physiology
  • 2011
Thermal energetics of N. bifax do not vary seasonally and in many aspects are similar in tropical and subtropical bats; however, torpid individuals from the subtropics allow body temperature to fall to significantly lower values than those from the tropics.
The effect of body mass and diet composition on torpor patterns in a Malagasy primate (Microcebus murinus)
The propensity of animals to enter torpor is directly influenced by age and seasonal changes in body mass, and thus reflect important physiological aspects of flexible thermoregulatory responses.
The importance of temporal heterothermy in bats
The importance and evolution of heterothermy in bats is summarized to understand the ecology and physiology of torpor in this largely understudied and cryptic mammalian group.
Stressful summers? Torpor expression differs between high- and low-latitude populations of bats
Summer skin temperatures of individuals from 2 populations of New Zealand lesser shorttailed bats were monitored to demonstrate that small differences in Ta differentially affect energetic strategy and thermoregulatory behavior of species inhabiting latitudinal gradients in climate is highly plastic.
Free-ranging bats alter thermoregulatory behavior in response to reproductive stage, roost type, and weather
The data showed that Indiana bat heterothermy was influenced by reproductive stage, roost choice, and weather, and managers should offer maternity colonies an array of refugia to facilitate varying behaviors in response to weather and energetic demands.


Torpor use by Free-ranging Pallid Bats (Antrozous pallidus) at the Northern Extent of Their Range
Torpor duration increased as mean daytime Ta decreased albeit the relationship differed between individuals and there was no significant effect of individual on the relationship between minimum Tskin during torpor and Ta.
Hibernation by a free-ranging subtropical bat (Nyctophilus bifax)
It is shown that prolonged torpor is an important component of the winter ecology of a subtropical bat and that torpor and activity patterns of N. bifax predominantly reflect prevailing weather conditions.
Torpor, thermal biology, and energetics in Australian long-eared bats (Nyctophilus)
The study suggests that Australian Nyctophilus bats have a low basal metabolic rate and that their patterns of torpor are similar to those measured in bats from the northern hemisphere.
The key to winter survival: daily torpor in a small arid-zone marsupial
This study shows that for wild stripe-faced dunnarts daily torpor is an essential mechanism for overcoming energetic challenges during winter and that torpor data obtained in the laboratory can substantially underestimate the ecological significance ofdaily torpor in the wild.
Metabolic rate and body temperature reduction during hibernation and daily torpor.
  • F. Geiser
  • Biology
    Annual review of physiology
  • 2004
The comparative analysis provided here suggests that MR reduction depends on patterns of torpor used, the state of tor porpor, and body mass, which in turn affects metabolic inhibition and energy conservation.
To use or not to use torpor? Activity and body temperature as predictors
These new findings suggest that before entering torpor, sugar gliders, which appear to use torpor as an emergency measure rather than a routine energy saving strategy, systematically reduce activity times and normothermic resting Tbs to lower energy expenditure and perhaps to avoid employing torpor.
Natural Use of Heterothermy by a Small, Tree‐Roosting Bat during Summer
It is indicated that torpor use is important for energy maintenance during summer diurnal roosting of N. geoffroyi and likely of other small, tree‐roosting bats.
Torpor and activity patterns in free-ranging sugar gliders Petaurus breviceps (Marsupialia)
It is shown that cold or wet conditions curtail foraging in wild sugar gliders and that they employ daily torpor regularly during adverse weather, which suggests that minimisation of energy loss by the use of torpor in sugar glider is pivotal for their survival in the wild.
The Role of Energy Availability in Mammalian Hibernation: A Cost‐Benefit Approach
It is suggested that trade‐offs between the benefits of energy conservation and the physiological costs of metabolic depression can explain both why hibernators periodically arouse from torpor and why they should use available energy to minimize the depth and duration of their torpor bouts.
The incidence of torpor in winter and summer in the Angolan free-tailed bat, Mops condylurus (Microchiroptera: Molossidae), in a subtropical environment, Mpumulanga, South Africa
Results indicate that M. condylurus maintained an optimally small Tb–Ta differential by readily becoming torpid under roosting conditions, thereby minimizing energy expenditure.