Variable color patterns influence continental range size and species-area relationships on islands

It has been hypothesized that species with more variable color patterns should have higher establishment success and be less sensitive to environmental changes and local extinction compared with species that do not vary in color. This difference in colonization/extinction balance should manifest as larger continental range distributions and modulate the species-area relationship on true islands. We evaluated these predictions using data for 1216 species of butterflies and moths that differed with regard to inter-individual variation in color pattern. We show that species with more variable color patterns have larger continental range sizes in Europe compared with non-variable species. We also provide rare evidence that the slope of the species-area relationship on islands is steeper for species having non-variable color patterns, suggesting that to preserve 60% of non-variable species would require an area twice as large compared to what would be needed to preserve 60% of variable species. Our findings suggest that combining information on ecological characteristics with presence/absence data from small and medium sized islands can help identify traits that drive species range patterns at the continental scale, and that individual variation in color pattern can be used as a proxy for ecological generalization and the ability to cope with environmental change.