Basal and cold-induced metabolic rates in the harvest mouse Micromys minutus

Abstract

Grodziński W., Bockler H. & Heldm aier G., 1988: Basal and cold-induced metabolic rates in the harvest mouse Micromys minutus. Acta theriol., 33, 20 : 283—291 [With 2 Tables & 2 Figs] The oxygen consumption in European harvest mice Micromys minutus (Pallas, 1771) was measured using a computerized open flow respirometr, at ambient temperatures ranging from +30 to — 10°C. For warm adapted spring animals, a temperature of — 10°C lies below their cold lim it. The basal metabolic rate (BMR) determined at +30°C was 2.86 ml 0 2g _1h ~ 1, which is very close to that predicted (2.55 ml 0 2g-1 h _1) from the allometric function scaling rodents' BMR/body weights. The relationship of the resting metabolic rate of the harvest mice (RMR in ml 0 2g ~ 1h-1 , and ambient temperature (Ta) from 0°C through + 30°C can be described by the regression: RM R= 12.063—0.305XTa. All the BMR and RMR values are much lower (1.8—2.2 and 1.4— 1.8 times lower) than in previous studies with nonrecording closed circuit respirometers. The energy strategy of the five sm allest rodent species (7—10 g) is discussed, including torpor, hibernation, and behavioural adaptations.