The relationship between rate of oxygen consumption, heart rate and thermal conductance of the dik-dik antelope (Rhynchotragus kirkii) at various ambient temperatures.
1. The extent of cardiovascular adjustments to heat and cold were investigated between ambient temperatures of 5 and 45 degrees C by measuring conductance and the rates of oxygen consumption and heart beats. 2. Minimum heart rate was observed at 25 degrees C (114 +/- 9 beats/min). In the heat at 45 degrees C heart rate was observed to increase only slightly (127 +/- 12 beats/min) but in the cold -5 degrees C heart rate nearly doubled that at 25 degrees C. 3. Thermal conductance was on average 0.031 mlO2 (g. hr. degrees C)-1 below 25 degrees C but increased by more than 20 times at 40 degrees C. 4. A positive correlation between heart rate and rate of oxygen consumption was demonstrated below 25 degrees C and the relation may be of practical use.
D000222:Adaptation, Physiological; D000818:Animals; D000866:Antelopes / Q000502:physiology*; D001188:Artiodactyla / Q000502:physiology*; D001833:Body Temperature Regulation; D002320:Cardiovascular Physiological Phenomena; D004777:Environment; D006339:Heart Rate; D010101:Oxygen Consumption; D013696:Temperature; D013814:Thermal Conductivity