Fig. 1

Cranial difference between captive and wild populations of individual mammal species. Forest plot of each meta-analysis for a: skull length, b: skull width, and c: skull length-to-width. Phylogenies shown to the left of each meta-analysis plot were pruned from Upham et al. [105]. Mammalian orders are indicated by color on the phylogeny: red=Carnivora, green=Perissodactyla, blue=Primates, purple=Dasyuromorpha, yellow=Diprotodontia, and gray=Rodentia (see Table 1 for additional taxonomic information). Colors within the plot indicate the sex of the specimens from each study: magenta=females, blue=males, and green indicates a study that used a pooled sample of both sexes. Summary effect sizes for directional analyses as well as analyses of magnitude are indicated in black. Forest plot lines that do not cross the dotted zero line are associated with a significant effect (i.e., the effect is not zero). Red arrows on the skull illustrations indicate the morphology associated with the positive and negative effect sizes on each plot