Thermal Biology, Torpor, and Activity in Free‐Living Mulgaras in Arid Zone Australia during the Winter Reproductive Season

@article{Krtner2008ThermalBT,
  title={Thermal Biology, Torpor, and Activity in Free‐Living Mulgaras in Arid Zone Australia during the Winter Reproductive Season},
  author={Gerhard K{\"o}rtner and Chris R. Pavey and Fritz Geiser},
  journal={Physiological and Biochemical Zoology},
  year={2008},
  volume={81},
  pages={442 - 451}
}
Little is known about the energy conservation strategies of free‐ranging marsupials living in resource‐poor Australian deserts. We studied activity patterns and torpor of free‐living mulgaras (Dasycercus blythi) in arid central Australia during the winter of 2006. Mulgaras are small (∼75 g), nocturnal, insectivorous marsupials, with a patchy distribution in hummock grasslands. Mulgaras (six males, three females) were implanted intraperitoneally with temperature‐sensitive transmitters and… 
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TLDR
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References

SHOWING 1-10 OF 57 REFERENCES
Torpor in Free‐Ranging Tawny Frogmouths (Podargus strigoides)
TLDR
It is concluded that despite their large body size and energetically conservative hunting strategy, tawny frogmouths, like several related caprimulgiform species, frequently enter shallow torpor when low Ta demands high energetic costs for normothermic thermoregulation and likely reduces insect availability.
Torpor and activity patterns in free-ranging sugar gliders Petaurus breviceps (Marsupialia)
TLDR
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.
Daily torpor during the active phase in free‐ranging rock elephant shrews (Elephantulus myurus)
TLDR
It is suggested that the principal benefit of a flexible daily rhythm of T b was that it facilitated arousal by passive exogenous heating using ambient temperature cycles.
Natural Use of Heterothermy by a Small, Tree‐Roosting Bat during Summer
TLDR
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 basking in a small arid zone marsupial
TLDR
The findings suggest that although overlooked in the past, basking may be widely distributed amongst heterothermic mammals and the energetic benefits from torpor use in wild animals may currently be underestimated.
Thermoregulatory ecology of a solitary bat, Myotis evotis, roosting in rock crevices
TLDR
The interaction between thermoregulatory behaviour and roost choice in reproductive female Western Long-Eared Bats, Myotis evotis (H. Allen), roosting solitarily in natural rock crevices is investigated, showing adaptive, but differ from those of other temperate-zone insectivorous bats that have been studied in the past.
Daily torpor in the gray mouse lemur (Microcebus murinus) in Madagascar: energetic consequences and biological significance
TLDR
All these energy-conserving mechanisms of the nocturnal mouse lemurs, with passive exogenous heating during arousal from torpor, low minimum torpor Tbs, and extended torpor bouts into the activity phase, comprise an important and highly adapted mechanism to minimize energetic costs in response to unfavorable environmental conditions and may play a crucial role for individual fitness.
The energetic cost of arousal from torpor in the marsupial Sminthopsis macroura : benefits of summer ambient temperature cycles
TLDR
The total cost of all three phases of torpor (entry, maintenance and arousal) was almost halved when animals were exposed to an ambient heating cycle from 15 °C to 25‬C over a 24-h period, and may represent an important energetic aid to free-ranging animals.
TORPOR IN RELATION TO REPRODUCTION IN THE MULGARA , DASYCERCUS CRISTICAUDA ( DASYURIDAE : MARSUPIALIA )
TLDR
This study demonstrates that the pattern of torpor in D. cristicauda is similar to that of other dasyurid marsupials and provides further evidence that reproduction and Torpor in mammals are not always exclusive.
Exogenous passive heating during torpor arousal in free-ranging rock elephant shrews, Elephantulus myurus
Abstract. In the laboratory rock elephant shrews (Elephantulus myurus; mean body mass 56.6 g) displayed the lowest torpor Tb min yet recorded (ca. 5°C) in a placental daily heterotherm. It was
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