Fig. 1

Allometric relationship between adult mass and litter weaning mass in mammals: comparative analysis of six regression models. Scatter plot of the litter weaning mass versus the adult mass in mammals (N = 738 species). The scatter plot shows a clear allometric relationship between adult mass and litter mass at weaning age. The six lines represent the predictions stemming from six different regression models (SLR simple linear regression, PLMM phylogenetic linear mixed model, SMA standardised major axis regression, MA major axis regression, MSLR multiple linear regression, MPLMM multiple phylogenetic linear mixed model). For MSLR and MPLMM, the regression lines consider the mean (log₁₀) investment duration for all species.