Fig. 3. Residuals of free fatty acid (A), uric acid (B) and ß-hydroxybutyrate (C) levels from the analysis given in Table 1 versus the residuals of energy expenditure after removing the effects of initial body mass for birds flying for 10 h. This indicates whether an above- or below-average metabolite level was correlated with an above- or below-average energy expenditure given the initial body mass. Correlations were: (A) r=0.663, P=0.013, N=13; (B) r=0.399, P=0.177, N=13; (C) r=0.582, P=0.037, N=13.