Winter
During winter Tlc for both sexes decreased to 11°C ([Figure 3]). Regression equations of thermoregulatory metabolism for males and females in winter are not different from each other in either slope or intercept. These data, therefore, were combined into a single equation ([Table 5]). Slope and intercept of this equation are both lower (p<0.005 and p<0.05, respectively) than those for summer animals ([Table 5]). Identical results were obtained from comparisons using regressions derived from oxygen consumption expressed in terms of metabolic body mass (Mellen, 1963). Thermoregulatory costs at any temperature below 20°C were lower for winter than summer animals ([Figures 2],[ 3]).
Table 6.—Regression equations describing oxygen consumption (mL O2·g-1·h-1) of Procyon lotor at temperatures below their lower critical temperature in winter (A = females with radio transmitters, B = females without radio transmitters, C = males, I = x-intercept (°C), n = number of observations, R2 = coefficient of determination, X = chamber temperature (°C), and Y = oxygen consumption).
| Group | Equation | (n) | R2 | I |
|---|---|---|---|---|
| A | Y = 0.63 - 0.0158·X | (10) | 0.66 | 40.1 |
| B | Y = 0.72 - 0.0226·X | (11) | 0.71 | 32.1 |
| C | Y = 0.69 - 0.0200·X | (15) | 0.79 | 34.7 |
