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Journal of Comparative Physiology B

, Volume 166, Issue 5, pp 325–330 | Cite as

Summer torpor in African woodland dormiceGraphiurus murinus (Myoxidae: Graphiurinae)

  • P. I. Webb
  • J. D. Skinner
Original Paper

Abstract

We determined the effect of food availability (presence/absence) and ambient temperature (25/10°C) on daily energy expenditure and the use of activity and torpor in summer-acclimated captiveGraphiurus murinus. Daily energy expenditure declined logarithmically with duration of food deprivation at a mean rate of 11 and 31% per day at 25 and 10°C, respectively. The incidence of torpor in the presence of food at 25°C was low (one in seven individuals) and increased on a single day's exposure to 10°C and with duration of food deprivation. Use of torpor was highest during the day, varied between individuals, and torpor bouts of greater than 24h duration were not noted. With food deprivation, individuals at 25°C initially responded by reducing activity but remained euthermic while the same individuals at 10°C responded by increasing their use of torpor during the light period; this difference in response probably reflects a difference in the relative energetic benefits of torpor at different temperatures.

Key words

Torpor Daily energy expenditure Food deprivation African dormice,Graphiurus 

Abbreviations

BM

body mass

DEE

daily energy expenditure

RQ

respiratory quotient

SMR

standard metabolic rate

Ta

ambient temperature

Tb

rectal temperature

VO2

oxygen consumption

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Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • P. I. Webb
    • 1
  • J. D. Skinner
    • 1
  1. 1.Mammal Research InstituteUniversity of PretoriaPretoriaSouth Africa

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