TABLE 2.--Body mass in kg and basal metabolism (mL O_{ 2}·kg^{ -0.75}·h^{ -1}) of _Procyon lotor_ in summer and winter (s.d. = standard deviation and n = number of observations).
----------------+----------------------------------------------------- Season and sex | Body mass, ±s.d., (n) Basal metabolism, ±s.d., (n) ----------------+----------------------------------------------------- Summer | Trapped male | 4.41 ±0.70 (52) 780 ±112 (20) Captive male | 4.73 ±0.61 (22) 680 ±102 (8) Captive female| 4.67 ±0.88 (41) 618 ± 92 (13) Winter | Captive male | 5.34 ±1.39 (31) 704 ± 81 (19) Captive female| 4.49 ±0.98 (42) 667 ±139 (25) ----------------+-----------------------------------------------------
Within thermoneutrality, [.H]_{ b} (mL O_{ 2}·g^{ -1}·h^{ -1}) was 0.54 ±0.09 for trapped males in summer, 0.46 ±0.07 for captive males in summer, 0.42 ±0.07 for captive females in summer, 0.47 ±0.06 for captive males in winter, and 0.46 ±0.10 for captive females in winter (Figures 2, 3). Ratios of these measured values to those predicted by the Kleiber (1932, 1961:206) equation are 1.28, 1.12, 1.02, 1.17, and 1.09, respectively. To minimize the effect of body size (Mellen, 1963) and to facilitate comparisons between sexes and seasons and between captive and trapped animals, basal metabolism also was calculated as a function of metabolic body size (mL O_{ 2}·kg^{ -0.75}·h^{ -1}; Table 2). Based on this analysis, trapped summer males had a higher basal metabolism than captive males (p<0.025) or females (p<0.005) in either season (Table 2). There was no difference in basal metabolism between captive males and females in either summer or winter, and there was no seasonal difference in their basal metabolic rates (Table 2).
Minimum wet and dry thermal conductances were calculated using Eqs. 4 and 5
C_{ mw} = [.H]_{ r} / (T_{ b} - T_{ a}) Eq. 4
C_{ md} = ([.H]_{ r} - [.E]_{ eq}) / (T_{ b} - T_{ a}) Eq. 5
where C_{ mw} is wet and C_{ md} is dry conductance (mL O_{ 2}·g^{ -1}·h^{ -1}·°C^{ -1}); [.H]_{ r} is the lowest resting metabolic rate measured at each temperature (mL O_{ 2}·g^{ -1}·h^{ -1}); [.E]_{ eq} is oxygen equivalent for heat lost by evaporation [[.E]_{ eq} = mL O_{ 2}·g^{ -1}·h^{ -1} = [.E]·[lambda]/[gamma], where [.E] is evaporative water loss (mg·g^{ -1}·h^{ -1}), [lambda] is heat of vaporization for water (2.43 J/mg), and [gamma] is heat equivalent for oxygen (20.097 J/mL)]; T_{ b} is body temperature (°C); and T_{ a} is chamber air temperature (°C). Only data from animals equipped with temperature-sensitive radio transmitters were used for these calculations.