Fig. 1

Evolutionary relationships and plumage similarity among exemplar species. Climate partially determines variation in woodpecker plumage. Lines lead from tips of phylogeny (left) to centroid of each species’ geographic distribution and are coloured according to mean climate regime of each species. These species shared a common ancestor ~ 6.5 mya. The colour scale depicts a gradient from warm (yellow) to seasonally cold regions (blue). eBird records for these species are plotted in the same colours as large points on the map. All other eBird woodpecker records are overlaid as smaller points and coloured similarly. Plumage dendrogram (right) shows the plumage dissimilarity relationships among the same set of species. Veniliornis mixtus, long classified as a member of Picoides, is inferred to have invaded seasonal climates in the southern hemisphere, and accordingly evolved bold black and white plumage. Picoides fumigatus, long classified as a member of Veniliornis, is inferred to have invaded warm climates near the equator, and accordingly evolved dark, subtly marked plumage. Picoides pubescens and P. villosus are rather distantly related but largely sympatric; they are inferred to have converged on one another in plumage above and beyond what would be expected based on shared climate, habitat, and evolutionary history. Traditional scientific names are used in this figure to aid explanation, but the illustrated species are currently all members of an expanded clade, Dryobates. Illustrations © HBW Alive/Lynx Edicions, map by authors