O2 and CO2 concentrations in burrows of euthermic and hibernating golden hamsters

O2 and CO2 concentrations were measured in burrows of golden hamsters (Mesocricetus auratus, W.) simultaneously with body temperature. In sealed burrows of euthermic golden hamsters daily mean concentrations of 15.1 +/- 1.2% O2 and 5.7 +/- 1.2% CO2 were measured, the extreme values amounting to 10.0% O2 and 10.8% CO2. The gas composition showed a daily rhythm. During hibernation, the gas composition of the burrow changed significantly to 20.0 +/- 0.5% O2 and 1.8 +/- 0.8% CO2.