WINTER ENERGY-REQUIREMENTS OF BLUE GROUSE

We measured the effects of temperature (T(a)) on the metabolic rate of 6 blue grouse (Dendragapus obscurus) during winter with indirect resp iration calorimetry. The standard metabolic rate was 0.812 L O2 . (kg0 .734)-1 . h-1 and was 24% higher than that predicted allometrically. T he lower critical temperature (T(lc)) of fasted grouse was -5-degrees- C; metabolism increased linearly below -5-degrees-C. The heat incremen t associated with a Douglas-fir (Pseudotsuga menziesii) diet lowered t he T(lc) by 5-degrees-C. From -5 to -20-degrees-C, the metabolism of f asted and fed grouse increased by 30 and 12%, respectively. A positive winter energy balance was predicted for blue grouse from estimates of the field metabolic rate and the consumption and assimilation rates o f a Douglas-fir diet.