Fig. 1: Chronic exposure to warmer conditions alters the size- and temperature-dependence of metabolic rate.

a Temperature-corrected metabolic rates are elevated for smaller organisms and suppressed for larger organisms after chronic exposure to warmer conditions, seen as (b) a decline in their allometric scaling exponent. The dashed line is the three-quarter scaling expected from MTE. c Mass-corrected metabolic rates are suppressed at lower acute temperatures and elevated at higher acute temperatures after chronic exposure to warmer conditions, seen as (d) an increase in their activation energy (thermal sensitivity). The dashed line is the typical activation energy of 0.65 eV expected from MTE for heterotrophic metabolism. The bars in (b) and (d) represent standard error around the mean from partial residual analysis of linear mixed-effects models fitted in (a) and (c), respectively (see Table 1a for model parameters and the Supplementary Note for underlying R code). Colours of points and lines in all panels indicate the environmental temperature to which species have been chronically exposed (see graphical legends). Source data are provided as a Source Data file.