Measurements of Convective and Radiative Heat Transfer in Small Mammals

Abstract

The coefficient of convection and the effective surface area for the emission and absorption of thermal radiation are two physical characteristics of an organism that must be quantified before the energy budget of that organism can be calculated. These two parameters were measured by using internally heated, pelt-covered metal casts of four species of western chipmunks (Eutamias alpinus, E. speciosus, E. amoenus, and E. minimus). The casts were suspended in a vacuum and the effective radiating surface area (A_ee) was calculated from the wattage necessary to maintain a constant cast radiating surface temperature (T_r), T_r, and chamber surface temperature. The casts were placed in a wind tunnel and the coefficients of convection at different wind speeds were calculated from T_r, wattage necessary to maintain that T_r, air temperature, tunnel wall temperature, and total cast surface area.