Fig. 1. Path diagram of the `indirect' model tested with measured data. BMR, basal metabolic rate; NST, non-shivering thermogenesis; MMR, maximum metabolic rate; C, thermal conductance; m<sub>bBN</sub>, body mass recorded at the moment of BMR and NST measurement; m<sub>bM</sub>, body mass recorded at the moment of MMR measurement; m<sub>bC</sub>, body mass recorded at the moment of C measurement; u, residual error. The broken line shows the additional paths from variables other than m<sub>b</sub>, which were considered as indicators of body size: L<sub>f</sub> (foot length) and L<sub>b</sub> (body length). These variables were measured only for cold-acclimated individuals (the `small' dataset). Latent variables are in circles and manifest variables in rectangles. The small diagram at the upper left identifies the path model in Table 3 (see Results).