Allometry of respiratory and haematological parameters of arctic mammal

1. 1. The allometric relationships for minimum oxygen consumption and resting minute volume of summer acclimatized Arctic mammals were: V ̇o2 = 0.18 M0.62, V ̇min = 1.93 M0.77, and the exponents of these relationships decreased with decreasing ambient temperature. 2. 2. Oxygen extraction of small mammals in thermoneutrality was 4-5% and decreased at low Ta. Oxygen extraction of large mammals was lowest at high Ta. 3. 3. Expired air temperatures decreased with decreasing air temperatures and differed substantially for different species. 4. 4. Calculated evaporative heat loss in thermoneutrality varied from about 5-16% in different species due to differences in oxygen extraction and expired air temperature. 5. 5. Blood of Arctic mammals has high red cell count, high haemoglobin concentration and low red cell volume compared to temperature zone mammals suggesting hemoconcentration as a mechanism of cold adaptation. © 1979.