Journal of Comparative Physiology B

, 156:129

The influence of temperature and photophase on daily torpor inSminthopsis macroura (Dasyuridae: Marsupialia)

Authors

  • Fritz Geiser
    • School of Biological SciencesThe Flinders University of South Australia
  • R. V. Baudinette
    • School of Biological SciencesThe Flinders University of South Australia
Article

DOI: 10.1007/BF00692935

Cite this article as:
Geiser, F. & Baudinette, R.V. J Comp Physiol B (1985) 156: 129. doi:10.1007/BF00692935

Summary

  1. 1.

    Body temperatures (Tb) and rates of oxygen consumption (\(\dot V_{O_2 }\)) during torpor of the insectivorous marsupialSminthopsis macroura were determined at different ambient temperatures (Ta) and photophases.

     
  2. 2.

    Torpor was observed in the morning and usually commenced before the onset of dawn. In the afternoon animals were normothermic. The duration of torpor was usually between 3 and 9 h with a maximum of 17 h and 15 min.

     
  3. 3.

    All animals entered torpor spontaneously at aTa of 13°C, but if food was withheld torpor was induced below 17°C.

     
  4. 4.

    An increase in\(\dot V_{O_2 }\) andTb during torpor was observed below aTa of about 12°C. The body temperature below which endothermic arousal is no longer possible (the critical arousal temperature) was less than 15.1°C.

     
  5. 5.

    An eight hour phase shift of the dark-light cycle resulted in a corresponding shift in the diurnal torpor-activity cycle and it appears that light is an important cue for the timing of daily torpor.

     

Copyright information

© Springer-Verlag 1985