Table 4.—Polynomial regression equations describing evaporative water loss (mg·g-1·h-1) of Procyon lotor in summer and winter (X = chamber temperature (°C), Y = evaporative water loss, n = number of observations, R2 = coefficient of determination, and SEE = standard error of estimate).
| Season and sex | Equation | (n) | R2 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Summer | ||||||||||
| Trapped male | Y = | 0.1899 | + | 0.0114 X | + | 0.0011 X2 | - | 0.00002 X3 | (32) | 0.86 |
| SEE | 0.0885 | 0.0223 | 0.0015 | 0.00003 | ||||||
| Captive male | Y = | 0.2174 | + | 0.0192·X | + | 0.0009·X2 | - | 0.00003·X3 | (10) | 0.73 |
| SEE | 0.3983 | 0.0834 | 0.0048 | 0.00008 | ||||||
| Captive female | Y = | 0.0127 | + | 0.0943·X | - | 0.0060·X2 | + | 0.00013·X3 | (31) | 0.64 |
| SEE | 0.2218 | 0.0547 | 0.0036 | 0.00006 | ||||||
| Winter | ||||||||||
| Captive, both sexes | Y = | 0.1550 | + | 0.0426·X | - | 0.0025·X2 | + | 0.00006·X3 | (57) | 0.80 |
| SEE | 0.0734 | 0.0192 | 0.0013 | 0.00002 | ||||||
Thermoregulation at Low Temperatures
Body Temperature
Body temperatures in [Figure 6] are those recorded during metabolic measurements from animals equipped with surgically implanted, temperature-sensitive radio transmitters. Each point was recorded during the lowest level of oxygen consumption at each Ta. In both summer and winter, Tb's were lowest during metabolic measurements at Ta's around Tlc. At Ta's below Tlc, Tb's increased ([Figure 6]), which is an unusual response. Under similar conditions, other procyonids either maintain a nearly constant Tb or allow it to fall slightly (Müller and Kulzer, 1977; Chevillard-Hugot et al., 1980; Müller and Rost, 1983; Chevalier, 1985). For our raccoons, confinement in the metabolism chamber at low temperatures must have stimulated a greater than necessary increase in metabolic rate such that heat production exceeded heat loss, which caused Tb to become elevated.
