Non-Steady-State O2 Consumption and Body Temperature in the Shrew Crocidura russula monacha (Soricidae, Insectivora)

Abstract

Specific O2 consumption (Ṁo2) and body temperature (Tb) were studied in the white-toothed shrew Crocidura russula monacha. Ṁo2 and Tb oscillate almost in parallel with a frequency of 4.9–17.1·h⁻¹ and deviation from minimal values of 0.37–0.80 C and 0.40–0.96 ml STPD·(g·h)⁻¹, respectively, depending on ambient temperature (Ta). Minimal Tb changes with Ta from 33.75 C at Ta = 17 C to 37.60 C at Ta = 37 C. The minimal Ṁo2 in the thermoneutral zone (TNZ: 28-36 C) is 2.55 ml STPD·(g·h)⁻¹ ± 0.56 SD. Mean Tb in the TNZ is 36.40 C ± 1.2 SD. The minimal heat transfer constant is 0.414 ml O2·(g·h·C)⁻¹. The adjustment of minimal Tb to different Ta's and the parallel short-term oscillations of both Tb and Ṁo2 seem to be advantageous for this small mammal where energy saving is so important. The oscillations represent a distinct non-steady-state homeostatic pattern rather than an erratic nervous and restless character.