FIGURE 9.

Effects of population and seasonal rearing conditions on flight metabolic rates (MR). (a) CR monarchs had significantly greater flight MR when reared in autumn relative to summer. (b) Flight MR were slightly elevated in, but not significantly different between autumn and summer‐reared NA monarchs. (c) Mass‐corrected flight MR showed a similar pattern, with increased flight MR in autumn‐relative to summer‐reared monarchs (rearing, p = .03) and a larger magnitude of difference in CR monarchs. However, there was no statistically significant effect of the interaction (population × rearing, p = .50). Male and female data are plotted together, as the sexes did not differ in patterns of metabolic rate (Table 5).