Fig. 1From: Energy savings due to the use of shallow body temperature reduction in overwintering Northern CardinalsLinear relationship between metabolic rate and ambient temperature (T a) in summer- and winter-acclimatized Northern Cardinals. Regression equations are shown, where the slope represents whole-animal conductance. There was no difference in conductance as regression analysis showed no significant effect of season. Lower critical temperatures as determined by piecewise regression are noted with 95 % CI in parenthesesBack to article page