Fig. 1

a Location of study area and sampling locations in Wisconsin, with each site assigned an alphanumeric code. Color gradients depict variation in mean monthly maximum temperatures, and symbol shapes designate sites where either just Blanding’s turtles (circles), just snapping turtles (triangles), or both species (squares) were sampled. b-c Admixture bar plots (left) and maps of primary genetic clusters (right) for the E. blandingii target gene (b) and SNP (c) datasets. d-e Admixture bar plots (left) and maps of primary genetic clusters (right) for the C. serpentina target gene (d) and SNP (e) datasets