Fig. 4. The relationship between solar heat gain (SHG) and coat thermal resistance (r_c, of depressed fur; measured at a wind speed of 1 m s^-1) of six ground squirrel species (circles; round-tailed, rock, two antelope and two golden-mantled ground squirrels; data from Walsberg, 1988a,b, 1990; Walsberg and Schmidt, 1989) and for the numbat (asterisk; N=3). The regression line for ground squirrels is y=–0.36x+64.3 (r²=0.97), with 95% confidence limits for predicting a further point.