Abstract:
Body temperature (Tb) is an important physiological component that affects endotherms from the cellular to whole
organism level, but measurements of Tb in the field have been noticeably skewed towards heterothermic species and
seasonal comparisons are largely lacking. Thus, we investigated patterns of Tb patterns in a homeothermic, free-ranging
small mammal, the Damaraland mole-rat (Fukomys damarensis) during both the summer and winter. Variation in Tb was
significantly greater during winter than summer, and greater among males than females. Interestingly, body mass had only
a small effect on variation in Tb and there was no consistent pattern relating ambient temperature to variation in Tb.
Generally speaking, it appears that variation in Tb patterns varies between seasons in much the same way as in
heterothermic species, just to a lesser degree. Both cosinor analysis and Fast Fourier Transform analysis revealed substantial
individual variation in Tb rhythms, even within a single colony. Some individuals had no Tb rhythms, while others appeared
to exhibit multiple rhythms. These data corroborate previous laboratory work showing multiplicity of rhythms in mole-rats
and suggest the variation seen in the laboratory is a true indicator of the variation seen in the wild.
