Metabolic and respiratory responses of arctic mammals to ambient temprature during the summer

1. 1. Respiratory frequency (f), tidal volume (Vt) and minute volume ( V ̇min) of eight species and oxygen consumption ( V ̇o2) of six species of summer acclimatized Arctic mammals were similar to that of temperate zone mammals. 2. 2. In small mammals, V ̇o2 increases at low Ta resulted in augmented V ̇min through increased f and Vt, while in large mammals f was relatively constant at low Ta. 3. 3. Except in weasels, basal metabolism was similar in winter and summer. 4. 4. Mass-specific conductance exhibits similar slope on body mass in winter and summer acclimatized animals with a greater intercept for summer animals. 5. 5. Critical gradient (Tb-Tc) exhibits similar slopes on body mass for winter and summer animals with a greater intercept for winter animals. 6. 6. Both large and small Arctic mammals can operate at similar metabolic levels in winter and summer as a result of seasonal pelage changes. © 1979.